Pool Filter Replaces Unicel Filter Cartridge for Swimming Pool and Spa 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 Pre-Filters allow for quicker water balancing with fewer chemicals. Washing a filter will extend its life &amp; clean filters use less energy. The Jet Brush makes this quick and easy. Scum Magnets prevent scum andoil from making it to the filter for fewercleanings.