Check Valve Cartridge, 2/pk Back Catalog number: CTS-10600 Manufacturer: SCIENCIX Availability: 3 weeks Price on request - + Recommended CTS-10475 Sapphire Plunger Kit Price on request CTS-21089 Needle Seal (For pH 1-14, for operation up to 130 Price on request CTS-A11142 Tube Assy, Inject Outlet Price on request