prolube 44720 1/2″ 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. Explosion proof design, these do not produce pressure as they have a 1:1 operation & cannot be used with a flow meter. Recommended for use with diesel fuel, kerosene, lubricants, gear oil, engine oil, waste oil, brake fluid, naphtha, mold lubricants, antifreeze and waste water.