Baleen Filters 100 sq. ft. Pool Filter Replaces Unicel C-4999, Pleatco PRB100, Filbur FC-2397-Pool and Spa Filter Cartridges Model: AK-3053 Media Area 100 sq ft, 4 15/16" OD, Open Hole: 2 1/8" Top, Open Hole: 2 1/8" Bottom, 26 11/16" Long, AK-3053 1 Year Warranty - Baleen Filters are made from Durable and Efficient USA Made Reemay Fabric - Washable Fabric Extends Your Filter's Life 100 sq. ft. In-Line Filter for Rainbow RTL 100, Dynamic Series II RTL/RCF-100, Dynamic Series III, RTL/RCF-100, Dynamic Series V, DSC-100, replacement of Unicel C-4999, Pleatco PRB100 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