1. Easy to install: Installed between your face and the silicone of the mask interface, easy to install, simple, convenient and practical accessories. 2. Prevent indentation: The increased surface contact can also reduce the tension of the ventilator headband, reduce skin redness, strap marks and air leakage. 3. Breathable lining: It can effectively inhibit sweat and moisture, reduce skin irritation, and provide extra comfort when using the ventilator mask. 4. Cotton blended fabric: Made of high-quality cotton blended fabric, it is safe and environmentally friendly, soft and skin-friendly, protecting your skin from direct contact with the mask. 5. 4 nasal mask liners: There are 4 nasal mask liners available, enough to meet your usage needs. Suitable for all brands of ventilator mask head covers.