The Fisher & Paykel FlexiFit 431 Full Face Under The Chin CPAP / BiPAP Mask is one of the few masks ever designed with a true under-the-chin seal. Unlike traditional full face masks that sit above the chin, the FlexiFit 431 extends underneath the chin to provide additional support and help reduce air leaks caused by jaw drop during sleep.
This unique design makes the FlexiFit 431 an excellent choice for CPAP and BiPAP users who experience mouth leaks, struggle with maintaining a mask seal, or find themselves constantly tightening their headgear throughout the night.
The patented FlexiFit cushion automatically adapts to the contours of your face, while the Glider Strap technology allows natural movement during sleep without compromising the mask seal. The result is a stable, comfortable fit that remains secure even at higher therapy pressures.
Many CPAP users experience air leaking from the bottom of their full face mask when their jaw relaxes during sleep. While chinstraps may help, they are not always effective. The FlexiFit 431 addresses this issue directly with its innovative under-the-chin design, helping create a more reliable seal and reducing therapy interruptions. Ideal for CPAP and BiPAP users who experience mouth leaks, jaw drop during sleep, lower mask seal leaks, or mouth breathing, as well as those requiring higher therapy pressures and looking for an effective alternative to a traditional chinstrap.
Key Features:
- Unique under-the-chin full face design
- Covers both the nose and mouth
- FlexiFit self-adjusting silicone cushion
- Glider Strap technology for improved stability
- Designed to minimize leaks and improve comfort
- Suitable for CPAP and BiPAP therapy
In the box:
- (1) Mask
- (3) Cushions -Small, Medium and Large








I’v tried multiple full face masks and continue to experience leaks around the mouth or chin area. I purchased the Fisher & Paykel FlexiFit 431 from CPAPs Store USA and the free shipping was pretty quick. I tried for a few weeks before i shared my review and have to admit FlexiFit 431 Full face CPAP Mask is most effective solutions available for me. Its under-the-chin design addressed one of the ongoing issues I had with other full face masks – air leaks. This mask offers a secure and dependable seal. I don’t have to use chinstrap anymore with a full face mask.
very soft, comfy and easy to adjust