The PerformancePLUS™ Check Valve Cartridges are used with pumps that have the PerformancePLUS Cartridge Check Valve System installed. The PerformancePLUS Cartridge Check Valve System can be used as either an inlet or outlet valve in the Waters 1515, 1525, 515, and 600 HPLC pumps. The inlet check valves of the 2695, 2695D and the 2795 are also the PerformancePlus type. The check valve materials have been carefully specified for solvent compatibility with all HPLC mobile phases. The housing features a two-piece design that allows it to be removed so that the cartridge can be changed without disturbing the fitting on the housing.