The 1" Reduced Pressure Principle Assembly is used in high health hazard, potable water applications for protection from both backsiphonage and backpressure of contaminated water into the potable water supply. The wye pattern, bronze body design provides separate access to each check valve and the relief valve to reduce labor costs and repair time. Its short lay length eases replacement costs and installation time. The 975XL2 includes all the necessary components for managing your system, and is the simplest, best, and most reliable backflow preventer in the market today.