TORK Brand Star-Clear Cartridge Filter C100, C250, C500, C750 Series Pool Filter O-ring Replacement Kit Star-Clear Cartridge Filter C100, C250, C500, C750 Series Pool Filter O-ring Replacement Kit Includes Tank Gasket, Locking Knob O-ring, Drain O-ring Quality Replacement Parts by TORK Distributors Fits MODELS C-250, C-500, C-750, C-1000