[COMPATIBLE & WITH SLEEP EQUIPMENT MACHINES]- Fits for All , for PR System One Series, for SleepEasy Machine Each filter to fit your machine precisely.[ CLEANFLOW TECHNOLGY]- The reusable black foam filter is to block particulate matter, the disposable white ultra fine filter is to block fine particles. Use together to the cleanest air.[KEEP YOUR MACHINE RUNNING AND MORE EFFICIENTLY]- Not Only Do Filters Help Keep Your Lungs Clean, It Also Prevents Dust, Dirt, and Other Buildups from Entering Your Motor.[30 PCS ECONOMICAL SET]- Include 15 Pcs Reusable Black Foam Filters and 15 Pcs Disposable White Ultra Fine Filters, replace your filter two weeks is recommended.Colour: black + whiteMaterial: sponge + cottonPackage Contents:15 * Reusable Black Foam Filters15 * Disposable White Ultra Fine FiltersOnly 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.