Check Valve Cartridge, 2/pk Back Catalog number: CTS-10493 Manufacturer: SCIENCIX Availability: 3 weeks Price on request - + Recommended CTS-A126 Outlet Check Valve Assembly Price on request CTS-10984 Sparge Diffuser Price on request CTS-21089 Needle Seal (For pH 1-14, for operation up to 130 Price on request