The 450 Double Check Backflow Assembly is utilized in low health hazard applications for protection against both backsiphonage and backpressure of polluted water into the potable water supply. Shaped in the n-Pattern, the Model 450 is ideal for both new and retrofit installations in compact locations. The patented, center-stem guided Compound Check provides low headloss and reliable, superior performance. It also features a convenient single access cover to reduce maintenance downtime. Materials include a corrosion-resistant, epoxy-coated ductile iron body and access covers, and stainless steel fasteners and springs.