The pressure regulator lowers the water pressure coming from the water source to a set pressure. It keeps the drip system operating effectively and helps prevent blowouts of fittings and emitters when used properly. This pressure regulator is preset at 20 PSI and has a flow range from 0.1 to 8 GPM. Printed on the body is an arrow to indicate the direction of water flow. The device connects to 3/4 in. MPT; use with transition fittings to make other types of connections. Made of ABS.