Magnum Pro Calibration Pumps, MP-P & MP-V From East Hills Instruments Dual O-rings on all pistons to ensure zero leakage Compact (9”x 1.5”) Light Weight (1 lb) Rugged Delrin and anodized aluminum construction Max pressure on MP-P is 100 psi Max vacuum on MP-V is 28” Hg Oversized check valves for smooth controlled operation Extra large vernier adjustment range 1/8 NPT or (BSP for None U.S.A.)