Aqua Kleen AK-70008 150 sq. ft. 8000 Series Cartridge for Astral Filter 150 sq. ft., 8 15/16" OD, Open Hole: 3 3/4" Top, Open Hole: 3 3/4" Bottom, 24 7/16" Long, AK-70008 Exact Fit for Unicel: C-8415 Exact Fit for Pleatco: PAST150 Exact Fit for Filbur: FC-0903 Guaranteed Perfect Fit - Extremely Durable - Wash & Reuse - Most Energy Efficient - Withstands High Pressures & Temperatures