prolube 44721 air operated double diaphragm pump is driven by compressed air and designed for use in applications requiring large volume transfer in a very short time; no close fitting or rotating parts so liquid with high solids content and/or size can be easily pumped. Self-priming pump design (incorporating internal check valves) allows for high suction lift even at dry start-up and with heavier fluids; no close fittings or sliding parts are at risk. The pump can run dry without damage.