FiltPool FP-1756 Pool Filter Cartridge is compatible with systems that use C2030, CX481XRE, CX481XREPAK4, PA56L, C-7456, 717-145, PLPA56L Models, with 240 Sq ft. Total filtration area, 4 Pack. Dimensions and specifications of the cartridge. 3 ID Top and bottom (open hole). Nominal dimensions: 17-3/8″ L x 7″ OD x 3ID. 60 Sq ft per filter, 240 Sq ft. End caps are both open with polyurethane material to provide high impact and perfect seal, our core is injection mold creating more stability than drilled PVC pipe. Made with materials suitable for pool filtration use, this pack includes four cartridges designed for straightforward installation and routine cleaning through rinsing or periodic maintenance. This Box contains 4 Pool filter Cartridges.