The Apollo™ Model RP4A/RPLF4A Series Reduced Pressure Backflow Preventers provide maximum protection against back-siphonage or backpressure from substances that are hazardous to the potable water supply. The top accessed modular check valve cartridges provide captured springs, replaceable seats and reversible silicone seat discs. This Made in America assembly features ball valves with stainless steel handles and trim as standard and carries the five-year Apollo™ factory warranty.