Baleen Filters 65 sq. ft. Pool Filter Replaces Unicel C-5374, Pleatco PLBS75, Filbur FC-2971-Pool and Spa Filter Cartridges Model: AK-40081-4 4 Pack Media Area 65 sq ft, 5 5/16" OD, Open Hole: 2 1/8" Top, Open Hole: 2 1/8" Bottom, 14 13/16" Long, AK-40081 1 Year Warranty - Baleen Filters are made from Durable and Efficient USA Made Reemay Fabric - Washable Fabric Extends Your Filter's Life 65 sq. ft. Top Load Filter for Rec Warehouse S2/G2 Spa, replacement of Unicel C-5374, Pleatco PLBS75 Baleen Filters Top: Open Hole: 2 1/8" Bottom: Open Hole: 2 1/8" Guaranteed Perfect Fit - Extremely Durable - Wash & Reuse - Most Energy Efficient - Withstands High Pressures & Temperatures