This 2 1/2 inch stainless steel reduced pressure zone assembly backflow preventer help stop the reverse flow of liquids due to backpressure or backsiphonage, where potential health hazard exists. This extremely compact and lighter than a traditional designed assembly is approved for horizontal installation in accordance with the direction of the flow arrow. This assembly consists of a stainless steel body with a quick access sleeve, torsion spring check valves, resilient seated gate valves with non-rising stem, test cocks, and a corrosive resistant stainless steel bottom mounted pressure relief valve. This backflow assembly contains a flood sensor with SentryPlus Alert(R) technology to detect excessive water discharges from the relief valve. When activated through an add-on sensor connection kit, the flood sensor relays a signal that triggers notification of potential flooding to service personnel. The add-on sensor connection kit is available for building management systems and cellular communication.