Zodiac Jandy Cartridge Filter, CJ Series - CJ200, CJ250 Tank O-ring R0557900 Zodiac Jandy Cartridge Filter, CJ Series Tank O-ring R0557900 Fits Models: CJ200, CJ250, be sure you are ordering for the correct Jandy filter prior to purchase 12" OD O'ring Quality Replacement Part by TORK Distributors #11 in pic