The ResMed AirFit F40 is ResMed's smallest full face CPAP mask. It uses an AdaptiSeal cushion — soft silicone with no hard parts — that sits under the nose rather than over the bridge, giving a full face seal in a noticeably smaller, lighter mask than the AirFit F20.

Why choose the AirFit F40

• AdaptiSeal cushion – all-silicone with no rigid parts, so it flexes as you move and change position.
• Under-the-nose design – nothing sits across the bridge of your nose, which is where most red marks come from. ResMed reports that over 70% of users experienced minimal to no facial marking.
• QuietAir vent – diffuses exhaled air to keep the mask whisper-quiet for you and anyone next to you.
• Magnetic headgear clips – guide themselves into place, so the mask goes on and off easily in the dark.
• Four-point adjustment – set it once and the headgear holds its position.
• Wide field of vision – read, watch television or wear glasses right up to lights out.
• Genuine ResMed product, supplied complete with headgear.

AirFit F40 vs AirFit F30i vs AirFit F20

All three are full face masks. The difference is where the cushion sits and where the tube connects.

If you want the smallest possible full face mask, choose the F40. If tube drag is your main problem, the F30i routes the hose over your head instead.

Choosing your AirFit F40 size

The F40 is sized by cushion and headgear together. Please don't assume your size from another mask — the F40 sits differently from an over-the-nose mask.

• Small Wide cushion / Standard headgear
• Medium cushion / Standard headgear – the most commonly ordered combination
• Medium cushion / Small headgear – for smaller head sizes
• Large cushion / Standard headgear

If you are between sizes or unsure, contact us before ordering and we will talk it through.

What's in the box

• AirFit F40 mask frame
• AirFit F40 AdaptiSeal cushion (size as selected)
• Headgear with magnetic clips (size as selected)
• QuietAir vent ring and elbow
• User guide

Technical details

Important: this mask contains magnets

The AirFit F40 uses magnetic headgear clips. ResMed advises that masks with magnets are contraindicated for people with certain implants — including pacemakers, implantable defibrillators, neurostimulators, shunts, insulin pumps, aneurysm clips, stents, metallic ocular implants and metallic splinters in the eye — and for people in close physical contact with someone who has one.

If that applies to you, we stock non-magnetic alternatives. Please read the AirFit F40 user guide before use, and speak to your doctor if you are unsure.

Replacement parts

You do not need to replace the whole mask when one part wears out. We stock the AirFit F40 replacement cushion, AirFit F40 headgear and the QuietAir vent ring and elbow system separately. As a guide, cushions are usually replaced every one to three months and headgear every three to six months.

Frequently asked questions

Is the AirFit F40 a full face mask?

Yes. It seals around the mouth and under the nose, so it delivers therapy whether you breathe through your nose, your mouth or both. It is simply smaller than a traditional full face mask because it does not cover the bridge of the nose.

What is the difference between the AirFit F30 and the AirFit F40?

Both are compact under-the-nose full face masks. The F40 is the newer model and uses the AdaptiSeal all-silicone cushion with no hard parts, where the F30 uses a conventional cushion with a rigid frame section. The F40 is also smaller and lighter.

What mask setting should I use on my CPAP machine?

Select "Full Face" in your device's mask settings. If your machine offers a mask-fit or leak test, run it after fitting.

How do I clean the AirFit F40?

Wash the cushion daily in warm water with a mild liquid soap, and wash the headgear and frame weekly. Rinse thoroughly and allow to air dry out of direct sunlight. Do not use bleach, alcohol or scented cleaners.

Will the AirFit F40 work with my machine?

Yes — it uses a standard mask connection and works with ResMed, Philips, Löwenstein and other CPAP and bilevel devices.