Baleen Filters 35 sq. ft. Pool Filter Replaces Unicel C-4335, Pleatco PRB35-IN, Filbur FC-2385-Pool and Spa Filter Cartridges Model: AK-3015-4, 4-pack Media Area 35 sq ft, 4 15/16" OD, Open Hole: 2 1/8" Top, Open Hole: 2 1/8" Bottom, 9 1/4" Long, AK-3015 1 Year Warranty-Baleen Filters are made from Durable and Efficient USA Made Reemay Fabric - Washable Fabric Extends Your Filter's Life 35 sq. ft. EZ Twist Top Mount Skim Filter with Top Load Pressure for Bullfrog, Hydro Pool, Hydro Spa, Infinity, Sun Ray Cartridge, replacement of Unicel C-4335, Pleatco PRB35-IN 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