This Replacement filter cartridge is best suited to be placed in 8 SQ. FT. Pelican Rec, H20 Recreation. The respective product is 8 inch long and 5 inch wide with 2 ¼ inch open hole at the top and closed top. These replacement cartridges match well with the technical specifications of Filbur# FC-3712, Unicel # C-5301 and OEM# C5301. You can avail these sturdy products at an much discounted rates at our stores.