O-ring replacement * Fits hayward pro-grid, micro-clear vertical grid d.e. filter and pro plus series models s311sx, s311sxv, s360sx * Also fits pro series s210s, s244s, s310s and sand filter series s240, s200,s160t * Also compatible with Hayward Super Star-Clear Cartridge filter series C2000, C3000, C4000, C5000 * Weighs 1.3-pound