The Ralston DCAP-2FSA 650 psi (45 bar) Pneumatic Hand Pump with 1/4" Female NPT Gauge Connection features a rugged metal construction with two outlet ports for connections, a fine adjust piston, and a precision pressure vent. It is an exceptionally durable hand pump for use in the field for such applications as pressure calibration, testing and custody transfer. The rugged, all metal construction improves temperature and pressure stability. Two outlet ports allow the user to attach the pump to both the device under test and an external pressure reference, thus eliminating a tee. The fine adjustment piston allows the user to achieve an exact pressure for cardinal point pressure calibrations. Users can also pneumatic field calibrations on pressure transmitters, switches or gauges using an external pressure calibrator (sold separately) as the reference.