Baleen Filters 25 sq. ft. Pool Filter Replaces Unicel C-4625, Pleatco PRB25-IN-4, Filbur FC-2370-Pool and Spa Filter Cartridges Model: AK-3047-4, 4-pack Media Area 25 sq ft, 4 15/16" OD, Open Hole: 2 1/8" Top, Open Hole: 2 1/8" Bottom, 13 5/16" Long, AK-3047 1 Year Warranty - Baleen Filters are made from Durable and Efficient USA Made Reemay Fabric - Washable Fabric Extends Your Filter's Life 25 sq. ft. In-Line Filter for Dynamic Series I RDC-25, RDC-25S, Dynamic Series II RTL/RCF-25, Dynamic Series III RTL/RCF-25, replacement of Unicel C-4625, Pleatco PRB25-IN-4 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