4 Pack Carbon Replacement Filters for Winix 115115 Size 21 4 Disposable aftermarket 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 This product does not meet the AHAM verified CADR (Clean Air Delivery Rate) of a genuine Winix filter. Use of this product will reduce the stated performance in your Winix Air Cleaner Brand New Individually Sealed made in the USA