Aqua Kleen AK-8015 Unicel Replacement Filter Cartridge for Swimming Pool and Spa 70 sq. ft., 10 1/16" OD, Open Hole: 3/8" Top, Open Hole: 6" Bottom, 19 5/8" Long, AK-8015 Exact Fit for Unicel: C-9970 Exact Fit for Pleatco: PVAC70-6 Exact Fit for Filbur: FC-3105 Guaranteed Perfect Fit - Extremely Durable - Wash & Reuse - Most Energy Efficient - Withstands High Pressures & Temperatures