Three-speed synchronous drive motor assembly, choice of 150, 300 or 600 piston strokes per minute (SPM). Volume control is accomplished by an easy-grip control ring graduated in hundredths for stepless adjustment while running or at rest. Features dependable low dead volume design. Maximum pressure at low flows is 50psig; up to maximum flow it is 20psig, with repeat accuracy to better than 1%. Three position switch, Forward-Off-Reverse. Supplied with 1/4" O.D. compression fittings, 3-prong power cord. Operates at 110v, 60 Hz. Pump A.