When you are connecting your drip irrigation system to a water source, do not forget the pressure regulator. Without it, the excessive water pressure can blow out emitters and fittings, and damage your system. The pressure regulator lowers the water pressure to a set pressure so your drip system can work effectively-keeping your fittings and emitters in place, right where you need them. The 3/4 in. FPT X 3/4 in. FPT pressure regulator is preset at 30 PSI, and commonly used to connect an existing underground irrigation system with 3/4 in. MPT pipe to control the water pressure. Install with the directional arrow pointing in the direction of water flow. The pressure regulator is made of high-impact acrylonitrile butadiene styrene (ABS) treated with UV inhibitors.