How Does Airflow Affect Fragrance in Large Open Spaces?

How Does Airflow Affect Fragrance in Large Open Spaces?

 

★ For a passive diffuser a draught is the enemy — for a cold-air mist it is the delivery systemSOSA Vaayu ₹11,999 · Sukoon ₹1,899 · reed diffusers from ₹749 · free shipping above ₹499A portion funds girl-child education
★ SOSA Vaayu · airflow
Airflow is not one variable with one right answer — it changes sign depending on which format you own
★ ★ ★ ★ ★
★★★★★
"Our living-dining has three fans and a cross-breeze off the balcony. Two reed diffusers in it were pointless and I could not work out why until someone explained that the breeze was emptying them."
Meera R. Alibaug
Villa owner · open living-dining
★★★★★
"I had been switching the fans off to make the scent last. Turning them back on with the right machine was the actual fix. Same room, opposite instruction."
Ranveer S. Jaipur
Vaayu · 42-foot great room
★★★★★
"The bit that landed for me was that a machine with propulsion wants the room moving and a bottle with none wants the room still. Nobody sells it that way."
Anjali D. Bengaluru
Villa owner · Vaayu
★★★★★
"We run the ceiling fans on one all evening and the scent reaches the far end of the dining table now. Before, it stopped about six feet from the unit."
Harish K. Coimbatore
Open-plan ground floor
★★★★★
"I moved my Sukoon out of the draught line of the split unit and it went from useless to fine for the seating area. Free fix. I nearly bought a bigger machine first."
Pooja N. Gurugram
Sukoon ₹1,899 · placement
★★★★★
"Honest note about the 400ml being the whole supply for now was appreciated. I asked SOSA before buying rather than after, which is how it should be."
Vikram T. Goa
Vaayu ₹11,999 · villa
★★★★★
"Our living-dining has three fans and a cross-breeze off the balcony. Two reed diffusers in it were pointless and I could not work out why until someone explained that the breeze was emptying them."
Meera R. Alibaug
Villa owner · open living-dining
★★★★★
"I had been switching the fans off to make the scent last. Turning them back on with the right machine was the actual fix. Same room, opposite instruction."
Ranveer S. Jaipur
Vaayu · 42-foot great room
★★★★★
"The bit that landed for me was that a machine with propulsion wants the room moving and a bottle with none wants the room still. Nobody sells it that way."
Anjali D. Bengaluru
Villa owner · Vaayu
★★★★★
"We run the ceiling fans on one all evening and the scent reaches the far end of the dining table now. Before, it stopped about six feet from the unit."
Harish K. Coimbatore
Open-plan ground floor
★★★★★
"I moved my Sukoon out of the draught line of the split unit and it went from useless to fine for the seating area. Free fix. I nearly bought a bigger machine first."
Pooja N. Gurugram
Sukoon ₹1,899 · placement
★★★★★
"Honest note about the 400ml being the whole supply for now was appreciated. I asked SOSA before buying rather than after, which is how it should be."
Vikram T. Goa
Vaayu ₹11,999 · villa
Vaayu · waterless cold-air nebulisation · up to 1000m³ · under 38 dB · 5W 400ml in the box · 90+ days a fill · no separate refill oil sold today — ask SOSA first Free shipping above ₹499 · a portion funds girl-child education through Nanhi Kali

 

Founder Diaries · Large-Space Scenting · Airflow
By Sonal Sahani · ISIPCA Versailles 9 min read Updated August 2026
Every piece of advice I have ever written about reed diffusers treats moving air as a hazard. Keep the bottle away from the split unit, away from the fan, away from the open window, because a draught strips the reeds, empties the bottle weeks early and leaves the room smelling of very little. That advice is correct, and in a large open space it is also the thing that traps people. Once you move to a machine that atomises oil and pushes it out under pressure, air stops being the thief and becomes the courier. The variable does not just change value between formats — it changes sign.
Quick answers — read this first
The inversion in one line: a passive source releases and waits for the room; a nebuliser releases into the room and needs the room to be moving to carry it.

For reeds and ultrasonics: gentle incidental traffic is right. A direct draught from a split AC, a fan or an open window is the commonest cause of a weak large room and a bottle that finishes early.

For a cold-air machine like the Vaayu: ceiling fans on low and the AC circulating are helpers, not enemies. The dry nano-mist is what needs distributing, and the room's own currents do it.

The honest caveat: the Vaayu ships with 400ml of cold-air oil and SOSA does not currently sell a separate refill for it. Ask before you spend ₹11,999.
The short answer
Short answer: airflow decides whether fragrance is distributed or destroyed, and which of those happens depends entirely on whether your source has propulsion. A reed diffuser has none — it relies on the room to move what it releases, so it wants slow, incidental air and is ruined by a jet. A cold-air nebuliser makes its own initial velocity and produces a dry mist fine enough to stay airborne, so it uses the room's currents as a distribution network rather than fighting them.
The mechanism: a reed evaporates from a wet surface. Fast air over that surface raises the evaporation rate far above what the composition was dosed for — you lose oil quickly and the fragrance is swept past you in a stream too dilute to register. A nebuliser atomises undiluted oil into particles small enough that they behave like part of the air itself, so a fan that would have wrecked a reed simply spreads them further.
Shop: for a genuinely open volume, the SOSA Vaayu at ₹11,999 covers up to 1000m³ (about 2,000–3,000 sq ft) with app and onboard timers, adjustable intensity and under 38 dB of noise. For one normal room on demand, the Sukoon at ₹1,899 covers 270–320 sq ft. Free shipping above ₹499.
Straight answer
Does moving air help or hurt fragrance in a large open room?
1. It depends on whether the source has propulsion, and nothing else. That is the whole answer. A source with no propulsion is at the mercy of the air. A source that atomises under pressure is in partnership with it. Every contradictory piece of diffuser advice you have read comes from someone stating one case as though it were the general rule.

2. For a reed diffuser, a draught is the most expensive mistake you can make. Fast air across a wet reed raises the evaporation rate well past the level the composition was dosed for. You get a bottle that empties in weeks rather than the 6–8 a 50ml is rated for, and a room that still smells of nothing, because the fragrance is being carried away in a thin stream rather than accumulating.

3. For a reed diffuser, dead air is the second most expensive. In an alcove, behind a sofa or in a corner of a 40-foot room with nothing moving, the fragrance pools within a foot of the glass. The correct condition is neither: gentle incidental traffic, near a doorway or walkway, waist to chest height.

4. For an ultrasonic, the same rules apply with a small extra margin. A Sukoon has a tiny fan and a visible plume, so it throws a few feet on its own. Past that it is the room's job again, and a direct AC draught will still shred the plume before it reaches head height.

5. For a cold-air nebuliser, the instruction reverses. The Vaayu uses pressurised air to atomise undiluted oil into a dry nano-mist. Those particles stay suspended, so ceiling fans on their lowest setting and a circulating AC are exactly what you want. Turning the fans off to "protect" the scent is the wrong instinct here.

6. Air exchange is a separate variable from air movement. Movement distributes; exchange removes. An open window in an open-plan home does both — it stirs the air and replaces it — which is why an airy sea-facing living room is the hardest space in India to scent with anything passive.

7. Before you spend, run the free version. Put what you already own in gentle passing air rather than a jet, and see what changes over a week. A surprising number of "I need a bigger machine" emails end there.

The Vaayu is made in India, ships with four SOSA Hotel Collection fragrances at 100ml each, and a portion of every order supports girl-child education through Nanhi Kali.
TL;DR: passive formats want slow air and are destroyed by fast air — a draught empties a reed bottle early and leaves the room empty. A cold-air nebuliser wants the room moving, because the mist is the payload and the air is the courier. Diagnose your airflow before you buy anything larger.
SOSA Vaayu waterless cold-air nebulising scent diffuser
The format that works with the air
SOSA Vaayu · waterless cold-air nebuliser ₹11,999
Pressurised air atomises undiluted fragrance oil into a dry nano-mist — no water, no heat, no wet residue on floors or furniture. Rated up to 1000m³, roughly 2,000–3,000 sq ft depending on ceiling height. 400ml tank, 90+ days a fill, Bluetooth app plus onboard buttons, 1h / 4h / 8h / 24h timers, adjustable intensity, auto-stop and key-lock. Under 38 dB, 5W, 0.9 kg, freestanding or wall / HVAC mounted. Ships with four Hotel Collection fragrances at 100ml each. SOSA does not currently sell a separate Vaayu refill oil — check availability before you buy.

Part one — the inversion, in three mechanisms

I want to take the general statement apart, because "airflow matters" is the kind of sentence that sounds useful and changes nobody's behaviour. There are three separate physical things happening when air moves past a fragrance source, and they have different consequences for different formats. Understanding which of the three is dominant in your room is what tells you whether to switch the fans on or off — and, more usefully, whether the machine you are about to buy will behave better or worse than the one you already own.

1
MECHANISM ONE · THE COST SIDE
Fast air over a wet surface spends your oil for nothing
A reed diffuser works by capillary action and surface evaporation. Oil climbs the fibre, reaches the exposed length, and leaves at a rate set by how much surface is exposed, how volatile the composition is, and how quickly the air at that surface is replaced. Move the air fast and you replace it constantly, so the evaporation rate climbs well above what the composition was dosed for at six reeds. The oil goes somewhere; it simply does not go anywhere useful. In a large open room with a fan overhead or a split unit blowing across the console, the fragrance is picked up in a thin, fast, over-diluted stream and delivered to a wall thirty feet away in a concentration no nose will report. You lose the bottle and you do not get the room. It is the worst outcome available in this category, and it looks exactly like a weak product.
The tell: a 50ml that finishes in four weeks instead of six to eight, in a room that never smelled strong. That is a draught, not a fault.
2
MECHANISM TWO · THE OTHER FAILURE
Dead air is not safety — it is a fragrance in a jar
SOSA Sukoon ultrasonic cool mist diffuserSukoon₹1,899 · 270–320 sq ftPeople who have been burned by mechanism one over-correct into mechanism two. The bottle goes into a still corner, the fans go off, the room is sealed — and now the fragrance forms a small dense cloud around the source and stops. In a 12 × 14 bedroom that is survivable; the room is small enough that diffusion alone will eventually fill it. In a 40-foot open living-dining, molecular diffusion is far too slow to matter and you get a scented three-foot bubble in the middle of an unscented room. The Sukoon at ₹1,899 buys you a little margin here, because it has a small fan and pushes a visible plume, but its honest rating is 270–320 sq ft and that number assumes the room does some of the work. Neither format is designed to be its own weather system.
The tell: strong within a metre of the source, absent at the sofa. That is dead air, and no larger bottle fixes it.
3
MECHANISM THREE · THE INVERSION
A nebuliser hands the room a payload the air can actually carry
Cold-air nebulisation does something categorically different. Pressurised air is forced across undiluted oil and shears it into a dry nano-mist — particles fine enough that they behave less like droplets falling and more like a component of the air itself. There is no water to add weight, no heat, and nothing wet landing on a floor. Because the payload is already airborne and already at velocity, the room's own currents become the distribution network rather than a hazard. A ceiling fan on its lowest setting is now doing useful work. A circulating AC is now doing useful work. The same 1000m³ specification that sounds absurd for a passive source is achievable precisely because the machine is not asking a still room to do a job still air cannot do. This is why I describe the jump from reeds and ultrasonics to cold-air as a change of category rather than a bigger version of the same thing.

Part two — the same air condition, three different verdicts

Here is the table I wish existed when I started answering these emails. Read down your own room's air conditions and across to the format you own. The point is not that one column is better — it is that the same condition earns a different verdict in each one, which is why generic diffuser advice fails in large homes.

Airflow, format by format
One air condition, three verdicts
Air condition in the room Reed diffuser (no propulsion) Ultrasonic — Sukoon / Boond Cold-air nebuliser — Vaayu
Gentle incidental traffic ★ Ideal — the condition the format is designed for Ideal, plume reaches a few feet further Fine, but under-uses what you paid for
Sealed, still, nothing moving Pools at the bottle; large rooms read empty Plume rises and stalls; a small scented column Works, but distribution is slower than it needs to be
Ceiling fans on lowest speed Marginal — depends how far the bottle sits from the blade path Usable if the unit is out of the direct downdraught Actively helpful — this is the intended condition
Split AC blowing across the source Worst case: bottle empties early, room stays quiet Plume shredded before head height Helpful, provided the machine is not inside the jet
Central or ducted AC circulating Unpredictable — supply grilles are draughts, returns are dead spots Better than a split, still limited by the 270–320 sq ft rating The strongest case for this format — the duct loop distributes it
Windows open, genuine cross-breeze Poor — movement plus air exchange, both against you Poor for the same reason Reduced, because exchange removes what movement spreads
Double-height volume, warm air rising Stratifies out of reach; the room reads empty at head height Same problem, slightly higher starting point Mount low and aim into the traffic; see the placement note below
The honest caveat: no amount of airflow tuning turns a point source into a whole-floor solution. If your connected open volume is genuinely large, the free fixes on this page will improve a reed diffuser from bad to acceptable-nearby, not from bad to good-everywhere. Equally, a Vaayu at ₹11,999 in a 400 sq ft flat is money spent on capability you will never use — a Sukoon at ₹1,899 is the honest answer there.
Shop this guide
Three formats, three different relationships with moving air
The SOSA principle
Air is a thief when the source is passive and a courier when the source has propulsion.
This is why the same ceiling fan that ruins a reed diffuser is the thing that makes a cold-air machine reach the far end of a forty-foot room. Diagnose the format before you diagnose the room.

Part three — tuning the air you already have, and when not to buy

Before anyone spends ₹11,999, I would like them to spend an hour instead. Stand in the middle of the open space with everything running as it normally runs — fans, AC, whatever is open — and hold a strip of tissue at chest height. Walk the room slowly and watch it. You will find, in almost every Indian open-plan home, that the space divides into three zones: a fast zone directly under a fan or in front of a split unit, a slow zone along the traffic path between doorway and sofa, and a dead zone in at least one corner, usually the one containing the console table where the diffuser lives. Moving a passive source from the dead zone to the slow zone is free and frequently doubles what you perceive. Moving it out of the fast zone is also free and will visibly extend the life of the bottle.

Two more free adjustments are worth running before any purchase. First, reverse the instinct about fans if you already own a machine with propulsion: set ceiling fans to their lowest speed rather than off, and let them run while the machine runs. Second, separate movement from exchange. An open window is not a fan — it swaps the air rather than stirring it, and no format on this page can outrun a genuine cross-breeze in a large room. Close up for the hour before people arrive, run the machine into a room that is circulating but not exchanging, and open again afterwards if you like. And a note that applies to every format: ventilate first, fragrance second. A scent machine adds fragrance to a room; it does not clean the air, and I will not pretend otherwise. If a space smells of something you would rather it did not, the extractor and the window come first, and nothing on this page is a substitute for them.

Now the part that talks some readers out of the purchase. If your open volume is under roughly 800 sq ft of genuinely connected space and the airflow test above shows a decent slow zone, you do not need a cold-air machine. Two reed diffusers at opposite ends — a duo set from ₹1,548 — or one Sukoon at ₹1,899 placed in the traffic path will do the job for a seventh of the money. If your space is genuinely large, the airflow argument is the reason a Vaayu behaves differently rather than merely bigger, and it is a fair reason to spend. But there is one more thing to settle first. SOSA does not currently sell a separate Vaayu refill oil. The 400ml supplied in the box — four Hotel Collection fragrances at 100ml each — is the whole supply available today, and at 90+ days a fill that is a meaningful run but not an indefinite one. The water-based Hotel Collection sold for ultrasonic machines is a different product and does not go in a Vaayu, despite sharing scent names. If long-term supply matters to you, ask SOSA where refills stand before you commit, not after.

A reed diffuser asks the room for a favour. A nebuliser hands the room something it can already carry.
— Sonal Sahani, SOSA

Part four — what to change, in the order I would change it

Everything above as a sequence of decisions. The first four cost nothing. Most people reading this because their large room smells of nothing will get a real improvement somewhere in the first four and never reach the fifth.

The airflow edit
Free adjustments first, then the format change
Step What you are correcting Applies to Cost
1. Tissue-strip walk of the room ★ Finding the fast, slow and dead zones you actually have Every format Free · ten minutes
2. Move a passive source out of the dead zone into the traffic path Distribution — the room was never receiving it Reeds, Boond, Sukoon Free
3. Move a passive source out of the AC or fan jet Wasted oil and a short bottle life Reeds especially Free · and it extends the bottle
4. Stop exchanging air during the hour that matters Cross-breeze removing what you have just released Every format Free
5. Add a second source rather than a bigger one Output per bottle is fixed — two ends beat one middle Duo sets From ₹1,548
6. One Sukoon in the traffic path On-demand scent for a normal room, 270–320 sq ft Rooms up to about 320 sq ft ₹1,899
7. Change category — Vaayu cold-air Turns the room's airflow from a hazard into the delivery system Connected volumes up to 1000m³ ₹11,999
Not an airflow fix: a Megh 6L and ~100 hrs of runtime, but only ~215 sq ft — less coverage than the Sukoon Long unattended runtime and humidity, not reach ₹3,499
Honest notes for buyers: the Vaayu's coverage figure of up to 1000m³ is a manufacturer specification and it is a volume, not an area — the 2,000–3,000 sq ft translation depends entirely on your ceiling height. Real reach also varies with intensity setting, run hours, ventilation and season. SOSA does not currently sell a separate refill oil for the Vaayu; the 400ml supplied in the box is the fragrance available today, and the water-based Hotel Collection for ultrasonic machines is a different product that must not be used in a Vaayu. Confirm current refill availability with SOSA before purchasing if long-term supply matters. Reed oil never goes in a machine. The Megh at ₹3,499 is a runtime and humidity machine at ~215 sq ft, never a coverage upgrade. Warranty terms, installation service and app platform details are not something I can state here — ask SOSA. Free shipping above ₹499, and a portion of every order supports girl-child education through Nanhi Kali.
SOSA Sukoon 500ml ultrasonic cool mist diffuser
If the honest answer is one room
SOSA Sukoon · 500ml ultrasonic ₹1,899
Most people who write to me about airflow in a "large open space" turn out to have one normal room with a fan in it. The Sukoon covers 270–320 sq ft, runs 16–18 hours on low from a 500ml tank, and comes with a remote and steady / 2H / 4H timers plus three 15ml Hotel Collection fragrances in the box. Put it in the traffic path rather than under the split unit and it will do everything a room that size needs, at a seventh of the price of changing category.
SS
ISIPCA
Versailles
A note from Sonal

I spent the first two years of this business writing the same sentence: keep the bottle away from the AC. It is good advice and I stand by it. What I did not anticipate was how many people would carry that sentence into a completely different situation and apply it to a machine it was never written about. I have had villa owners tell me they switch off every fan in a forty-foot great room before running a cold-air diffuser, because they read on our own blog that draughts ruin fragrance. They were following my instructions and getting a worse result for it.

So this page exists to say the quiet part plainly. The rule was never "air is bad." The rule was always "a source with no propulsion cannot survive being outrun by the room." Once the source has propulsion and produces something light enough to stay up, the room stops being an obstacle and starts being infrastructure. That is not marketing; it is the reason a 1000m³ figure is possible for one machine and impossible for twenty bottles.

What I would ask, as ever, is that you run the free version first. Walk your room with a tissue strip. Move what you own. Give it a week. If the space is genuinely large and the format is genuinely the limit, the upgrade is a fair one — and if you go that way, please ask us about refill availability before you spend, because I would rather lose the sale than have you discover the gap in month four. Everything we make is composed in Pune, and a part of every order funds a girl's classroom through Nanhi Kali.

Frequently asked questions

Should I turn the ceiling fan off to make the fragrance last longer?
If your source is a reed diffuser, move the bottle out of the blade path rather than switching the fan off — you want gentle passing air, not a downdraught and not stillness. If your source is a cold-air nebuliser such as the Vaayu, leave the fans running on their lowest setting. The mist is designed to be carried, and stillness simply slows distribution.
Why does my reed diffuser empty quickly but never make the room smell?
That combination is almost always a draught. Fast air across the reeds raises the evaporation rate above what the composition was dosed for, so oil leaves quickly and is carried away in a stream too dilute to register. Move the bottle several feet from any AC vent, fan path or open window, out of direct sun, and onto a console in the traffic path at waist to chest height.
Does a cold-air diffuser work better in an air-conditioned room?
It generally distributes better, because a circulating AC keeps the room's air moving without exchanging it for outside air. A split unit blowing directly at the machine is not ideal, but a room whose air is being circulated is a good environment for a nebulised mist. It also suits a monsoon climate, since cold-air nebulisation adds no water to the room the way an ultrasonic does.
Can I fix a large open room by buying a bigger reed diffuser?
No. A 130ml bottle at ₹1,249–₹1,349 lasts 14–18 weeks against 6–8 for a 50ml, but at the same six reeds it projects about the same. Size buys duration, not reach. If one point source is not enough, the honest options are a second source at the opposite end, or a change of format.
Is the Megh a better choice for a large airy room since it holds 6 litres?
No, and this is worth saying clearly. The Megh at ₹3,499 holds 6L and runs about 100 hours, but it is rated at roughly 215 sq ft — less than the ₹1,899 Sukoon. It is a runtime and humidity machine, not a coverage upgrade. Buy it for long unattended running, never for reach.
Large-space scenting · airflow
Diagnose the air before you buy the machine — then pick the format that uses it
The SOSA Vaayu at ₹11,999 nebulises undiluted oil into a dry cold-air mist for connected volumes up to 1000m³ (about 2,000–3,000 sq ft), with app and onboard timers, adjustable intensity, key-lock and under 38 dB of noise, on 5W. It ships with 400ml of fragrance across four Hotel Collection scents; a separate Vaayu refill oil is not sold at the time of writing, so check with SOSA first. For one normal room, the Sukoon is ₹1,899. Free shipping above ₹499, and a portion of every order supports girl-child education through Nanhi Kali.
See the Vaayu → Sukoon ₹1,899
Continue the read
More on open-plan and large-volume scenting
Editorial standards & sources
About this guide: Written by Sonal Sahani, ISIPCA Versailles-trained founder and perfumer at SOSA Home & Body, on how moving air changes fragrance behaviour in large open volumes and why the correct instruction reverses between passive and nebulising formats. Airflow guidance here is SOSA's working experience from in-house testing and customer correspondence, not laboratory measurement; results vary with room volume, ceiling height, ventilation, AC type and season. No health, air-purification or odour-removal claim is made or implied — a scent machine adds fragrance and nothing else.

SOSA Vaayu specifications (verified from the live product page, August 2026): ₹11,999 (the product page displays a rounded ₹12,000). Waterless cold-air nebulisation — pressurised air atomises undiluted fragrance oil into a dry nano-mist; no water, no heat, residue-free. Coverage up to 1000m³, about 2,000–3,000 sq ft. 400ml refillable tank, 90+ days per fill at a mid intensity setting. Bluetooth app plus onboard buttons, 1h / 4h / 8h / 24h timers, adjustable mist intensity, auto-stop and key-lock. Under 38 dB. DC 12V / 1A, 5W. 165 × 80.5 × 215 mm, 0.9 kg, black or white. Freestanding or wall / HVAC mount. CE, RoHS and SGS certified. Ships with four SOSA Hotel Collection fragrances at 100ml each (400ml in total) in one of three combos chosen at checkout. SOSA does not currently sell a separate Vaayu refill oil; the 400ml supplied in the box is the fragrance available at the time of writing, and buyers who need long-term supply should confirm current refill availability with SOSA before purchasing. The cold-air oil supplied with the Vaayu is a different product from the water-based Hotel Collection sold for ultrasonic machines (15ml ₹299 · 100ml ₹999 · 300ml ₹1,799), which must not be used in a Vaayu despite sharing scent names. Other SOSA machines: Boond 300ml ₹899 (~150 sq ft) · Sukoon 500ml ₹1,899 (270–320 sq ft) · Megh 6L ₹3,499 (~215 sq ft — a runtime and humidity machine, not a coverage upgrade) · Aangan ₹25,999 (~8,000–10,000 sq ft) · Meenar ₹38,500 (12,000–18,000 sq ft) · Safar car diffuser ₹3,999. Reed diffusers 50ml ₹749–₹849 (6–8 weeks) · 130ml ₹1,249–₹1,349 (14–18 weeks) · duo sets ₹1,498–₹1,598 · oil-only refills 300ml ₹2,399 / 500ml ₹3,499. Runtime, consumption and coverage figures are manufacturer specifications and vary with intensity setting, run hours, ceiling height, ventilation and season; any per-month or per-day figure in this guide is arithmetic on those specifications, not a measurement. Electricity costs vary by state tariff. No claim is made that scenting affects ratings, reviews, bookings, occupancy, revenue, health, mood or air quality. Free shipping above ₹499. A portion of every order supports girl-child education through Nanhi Kali. Prices subject to change — see the live product pages.
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