: These filters are made of ultra-fine fiber cotton which can effectively filter fine particles, dust, and pollen. BPA-free, safe and reliable. Thickened Design: While other filters are only about 1mm thick, these filters are approximately 3mm thick, allowing them to capture fine particles, viruses, and other harmful substances in the air, enhancing the filtration performance of the respirator. Better Compatibility: Each filter measures 2 x 0.9 inches. The size is designed to fit Airsense 11 machines, minimizing gaps and improving filtration efficiency. Improve The Air Freshness: Each filter is designed to block fine particles and larger particulate matter, delivering cleaner and fresher air from the ventilator, helping to improve air quality and support patient health and sleep quality. Extend The Life of The Machine: These filters help prevent dust and impurities from entering the ventilator, reducing internal wear, lowering maintenance and cleaning costs, and extending the lifespan of the device. Color: White Material: Cotton Package Contents: 30 x Filters Note: Light reflection and different displays may cause the color of the item in the picture to appear slightly different from the actual product. Measurement allows an error of +/- 1-3 cm.