The 6'''' 350DARH Double Check Detector Backflow Assembly, with flanged end OS&Y gate valves and right handed threaded case valve, protects against backsiphonage and backpressure in low health hazard, fire protection applications. Featuring a metered bypass system, the 350DA efficiently and effectively detects leaks and any unauthorized water use, saving you added costs associated with maintenance and repairs. The Zurn Wilkins Compound Check provides low headloss, and backflow installation is approved in both horizontal and vertical positions.