The Great Lakes FILTER-10 replacement filter set is designed specifically for the FFKN12-A4 fan/filter assembly, compatible with NEMA12Kw all mounting configurations. Each pack contains five white filters made from a uniquely fluted filter mat, ensuring effective air filtration and protection. These replacement filters provide an easy and efficient way to maintain the performance of your fan/filter system. Upgrade your filtration with this convenient five-pack and keep your equipment running smoothly. Don't wait, purchase your replacement filters today to ensure optimal operation!