1100 Series Essential Pack, G1310A/G1311A Pump Back Catalog number: CTS-21586 Availability: In the manufacturer's stock Price on request - + Recommended CTS-10475 Sapphire Plunger Kit Price on request CTS-21011 Cartridge Check Valve System Kit Price on request CTS-A11094-02 UPLC Primary Check Valve Assy, 2/pk Price on request