4 Pack Carbon Replacement Filters for Winix 115115 Size 21 by Vacuum Savings 4 Disposable activated carbon pre-filters included for odor reduction For Winix plasma wave air cleaner models WAC5300, WAC5500, WAC6300, 5000, 5000b, 5300, 5500, 6300 & 9000 Will fit the WAC9500 PlasmaWave Ultimate pet air cleaner if you first remove the complete original cartridge that came with the WAC9500. Insert the 115115 replacement filter where the cartridge was, with the black carbon filter on top facing the front True HEPA Filter - Captures 99% of particles. Brand New Individually Sealed By LifeSupplyUSA