Check Valve, Cartridge Back Catalog number: CTS-21480 Availability: In the manufacturer's stock Price on request - + Recommended CTS-21089 Needle Seal (For pH 1-14, for operation up to 130 Price on request CTS-A11342 Tube Assembly, Transducer to Check Valve Price on request CTS-A11094-02 UPLC Primary Check Valve Assy, 2/pk Price on request