1. 500pcs bag, 100% high-quality non-woven fabric. 2. -each screen measures 53 x 35mm, precisely matching your machine. 3. Compatible with CPAP machines, suitable for AirSense 10 and AirCurve 10 to S9 series CPAP 4. Ultra-fine PM2.5 ultra- dust filter cotton, which can effectively filter extremely fine dust particles (PM2.5 level) in the air, ensuring that you get and improve air quality during the use of the ventilator. new and high quality. Disposable ultra-fine filter blocks fine particles. Effectively filter PM2.5 fine particle dust in the air. White filter cotton is recommended to replace 1-2 pieces in . Not only help you keep your lungs clean, but also prevent dust, dirt and other substances. Specification: Color: White. Material: Non-woven Size: About 53 x 35mm Package Contents: 500 x Filter membrane Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.