Check Valve Cartridge, 2/pk Back Catalog number: CTS-10600 Manufacturer: SCIENCIX Availability: 3 weeks Price on request - + Recommended CTS-10340 Plunger Seal Price on request CTS-21089 Needle Seal (For pH 1-14, for operation up to 130 Price on request CTS-21287 Needle Kit, 15 µL with Needle Seat and Needle Guid Price on request