[COMPATIBLE WITH CPAP MACHINES] - Fits all M Series, PR System One Series, and SleepEasy machines. Each filter is designed to fit your machine precisely. [PREMIUM CLEANFLOW TECHNOLOGY] - The reusable black foam filter helps block particulate matter, while the disposable white ultra-fine filter helps capture fine particles. Using them together helps deliver cleaner air. [HELP MAINTAIN MACHINE PERFORMANCE] - These filters help protect your device by reducing dust, dirt, and debris from entering the motor, helping your machine run efficiently. [30-PIECE ECONOMY SET] - Includes 15 reusable black foam filters and 15 disposable white ultra-fine filters. Replacement every two weeks is recommended for optimal performance. Color: Black + White Material: Sponge + Cotton Package Contents: 15 x Reusable Black Foam Filters 15 x Disposable White Ultra-Fine Filters Note: Light reflection and different display screens may cause slight color variations between the image and the actual item. Measurement may vary by +/- 1-3 cm.