Black Plunger Seal Back Catalog number: CTS-6613 Manufacturer: SCIENCIX Availability: 3 weeks Price on request - + Recommended 11-2401 Check Valve Cartridge, Ceramic Ball & Seat, 2/pk Price on request CTS-A094 Check Valve Cartridge, 2/pk Price on request CTS-2294 Plunger Seal Price on request