prolube 44722 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 adblue/def, antifreeze, ethanol, ammonium hydroxide and waste water.