100 pcs bag, 100% high-quality non-woven fabric. Perfect fit—each screen measures 53 x 35 mm, precisely matching your machine. Compatible with various CPAP machines, suitable for ResMed AirSense 10, AirCurve 10, and S9 series CPAP devices. Ultra-fine PM2.5 air filter cotton effectively captures fine dust particles (PM2.5 level), helping to ensure clean airflow and improved air quality during ventilator use. High-quality, new condition. Fine filtration helps block small particles and dust. Replace filter cotton every 1 to 2 months for optimal performance. Helps maintain clean lungs and reduces exposure to dust, dirt, and other airborne particles. Specification: Color: White. Material: Non-woven fabric. Size: Approximately 53 x 35 mm. Package Contents: 100 x Filter membranes. Note: Light shooting and different displays may cause slight color variations between the image and actual item. Measurement error allowed within +/- 1-3 cm.