Hayward C200S SwimClear Cartridge Pool Filter, 200 Square Foot, Single Element Industry-leading hydraulic efficiency allows the pump to run at a lower speed or for less time, increasing energy savings Easy-Lok ring design allows quick access to internal components for quick and simple maintenance Recessed pressure gauge and manual air relief enables user to place head assembly upside down on pool pad, protecting the seal from contamination 2" x 2 1/2" union connections make installation and servicing fast and easy