This 3/4 inch freeze resistant pressure vacuum breaker backflow preventer helps prevent the reverse flow of polluted water from entering into the potable water supply due to backsiphonage. It consists of bronze body construction, silicone rubber check valve disc, plastic check valve seat, stainless steel springs, a bonnet with silicone rubber O-ring seal, a lightweight plastic disc float, a built-in relief valve to protect the internal components and the body from freezing, tee handle shutoffs, union connections, and test cocks for winterization draining.