Compatible with Winix Filter A 115115 True HEPA Filter, Plus 8 Replacement Carbon Activated Pre-Filters. Size 21 filter. Compatible with Winix air cleaner models 6300, P300, 5300, 5300-2, 6300-2, and C535. Compatible with Winix plasma wave air cleaner models WAC5300, WAC5500, WAC6300, 5000, 5000b, 5300, 5500, 6300 & 9000WAC5300, WAC5500, WAC6300, 5000, 5000b, 5300, 5500, 6300 & 9000 Packaging may vary. This is not a Winix OEM product. Winix brand names and logos are the registered trademarks of their respective owners. Any use of the Winix brand name or model designation for this product is made solely for purposes of demonstrating compatibility.