Unicel C-7660 Spa Replacement Cartridge Filter 60 GPM Pac-Fab and Wet Institute Industry's most complete line of replacement filter elements Endless Pools Pentair Pool Prod (172810) (Note: Two 60 sq.ft. cartridges required) Pentair Pool Prod (R173298) Pentair Pool Prod Pac Fab Replacements (17 2810)