[COMPATIBLE WITH VARIOUS SLEEP EQUIPMENT MACHINES] - Fits all M Series, PR System One Series, and SleepEasy machines. Each filter is designed to fit your machine precisely. [PREMIUM QUALITY CLEAN FLOW TECHNOLOGY] - The reusable black foam filter helps block large particulate matter, while the disposable white ultra-fine filter captures fine particles. Using them together helps provide cleaner air. [KEEP YOUR MACHINE RUNNING LONGER AND MORE EFFICIENTLY] - These filters help keep your machine clean by preventing dust, dirt, and debris from entering the motor, supporting optimal performance. [50 PCS ECONOMICAL SET] - Includes ultra-fine filters. Replacement every two weeks is recommended for best results. Color: Black Material: Sponge Package Contents: 50 * CPAP Filters Note: Light reflection and different displays may cause slight color variations between the image and the actual item. Measurement error is +/- 1-3 cm.