Aqua Kleen AK-6088 Unicel Replacement Filter Cartridge for Swimming Pool and Spa 150 sq. ft., 7 7/8" OD, Open Hole: 3 1/16" Top, Open Hole: 3 1/16" Bottom, 33 3/8" Long, AK-6088 Exact Fit for Unicel: C-7679 Exact Fit for Pleatco: PFAB150 Exact Fit for Filbur: FC-1960 Guaranteed Perfect Fit - Extremely Durable - Wash & Reuse - Most Energy Efficient - Withstands High Pressures & Temperatures