Welcome to the store! [COMPATIBLE & PERFECT FIT WITH SLEEP APPLIANCES] - Fits all M-Series, PR System One Series, and SleepEasy machines! Each filter is precisely designed for your machine. [PREMIUM QUALITY CLEANFLOW TECHNOLOGY] - The reusable black foam filter blocks larger particles, while the disposable white ultra-fine filter blocks fine particles. Use them together for the cleanest air possible. [KEEP YOUR MACHINE RUNNING LONGER & MORE EFFICIENTLY] - Our filters not only help keep your lungs clean but also prevent dust, dirt, and other buildup from entering your machine's motor. [30 PIECE ECONOMICAL SET] - Includes 15 Reusable Black Foam Filters and 15 Disposable White Ultra-Fine Filters. It is recommended to replace the filter every two weeks. Color: black + white Material: sponge + cotton Package Contents: 15 * Reusable black foam filters 15 * Disposable white ultra-fine filters 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. Your satisfaction is our top priority. We will provide you with the best service. If you find any problems after receiving the product, such as damage, incorrect quantity, etc., please contact us immediately and we will give you the best solution!