Designed to provide the best protection and durability against backflow caused by negative or opposite pressure. Backflow may cause infiltration of chemicals, fertilizers and/or other pollutants into drinking water systems. The DC, RP and PVB series are reliable and easily maintained, and do not require special tools for installation or repair. ARI has several model types to cover your recommended degree of water protection. The bodies of these backflow prevention assemblies are made of a UV resistant glass reinforced nylon that help to prevent issue related to theft.