Hayward Filter, Swim Clear, Generic Bulkhead Replacement O-Ring. Same as: SX220Z2 Fits Max-flo II pump series SP2700X models SP2705X7(EE), SP2707X10/2, SP2710X15/2, SP2715X20/2 Also fits Hayward Pro-grid Vertical Grid D.E and swimclear cartridge filter series models DE7220, C5030, C3025