Inexpensive and reliable Air Operated Pump gently pressurizes drum at 4 - 7 psi. Built in automatic safety pressure vent relieves pressure above 7 psi. 100% polypropylene construction handles acids, caustics, oils, coolants, cleaners, and many others. Self-priming, delivers up to 16 gallons per minute of 250 centipoise liquid, up to 15’ high. Quiet operation. Installs quickly in 2” NPT bung. Includes 3’ x 3/4" polypropylene dispensing hose, 10’ x 1/4" air line and 34-1/2" polypropylene suction tube. Optional Air Pressure Regulator prevents wasted air by pre-regulating air supply greater than 7 psi up to 250 psi. Locking calibration knob. Optional Hand Flow Nozzle allows precise flow control. Polypropylene body with Viton® and stainless steel internals.