Polyester construction, EPDM o-ring metal, EPDM gasket metal, EPDM hose metal, polyester suction tube. Some acids, caustics, ketones, acetates compatible liquids. This double-action piston pump is self-priming and delivers on the forward and the back stroke. Less than five cycles yields a gallon (3 .8 liters). The two position handle may be mounted either above or below the pump. The handle can be padlocked to prevent unauthorized dispensing. A built-in siphon breaker prevents unwanted flow when pumping is stopped. It will operate wet or dry without damage. Unlike ordinary metal hand pumps, it will even handle fresh or salt water. Rust is no problem here!