Baleen Filters AK-90311 Pool Filter Cartridges, 8 x 8 x 6 inches, White Media Area 50 sq ft, 8" OD, Semi Circular Handle Top, Open Hole: 2" Bottom, 6" Long, AK-90311 Media Area 50 sq ft, 8" OD, Semi Circular Handle Top, Open Hole: 2" Bottom, 6" Long, AK-90311 50 sq. ft. Top Load Filter for Bullfrog, Diamante, US Tooling Cartridge, replacement of Unicel 8CH-950, Pleatco PBF50-F2S Baleen Filters Top: Semi Circular Handle Bottom: Open Hole: 2" 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.