Features： 1、OE Number: The replacement part number is 571 VAC CHK A. Please check the part numbers whether it suits your vehicle before purchasing. This backflow preventer valve gives you a high level of peace of mind when exploring the outdoors. 2、High Performance: Crafted from premium brass, the use of an integrated spool provides enhanced durability with improved sealing and quieter operations. It offers high sensitivity to water pressure and can withstand pressures ranging from 8-125 PSI. 3、Powerful Function: This vacuum breaker valve is designed to prevent backflow and back siphonage in the black tank flushing system. It ensures the cleanliness and health of your freshwater source. 4、Easy Installation: Featuring 1/2in NPT male threads on both the inlet and outlet, this valve allows for easy installation. The correct installation direction is indicated by the "FLOW" arrowhead on the valve body, ensuring proper water flow. 5、Wide Compatibility: Suitable for various RV models including for Forest River, for Keystone Passport, for Winnebago 2018, and more. The check valve is designed for RVs, travel trailers, and motorhomes, providing water safety and peace of mind during your journeys. Specification： Item Type: RV Vacuum Breaker Check Valve Material: Brass OE: 571 VAC CHK A Fitment: Replacement for Forest River Replacement for Grey Wolf 21 Replacement for Wilderness 2014 Replacement for Keystone Passport Replacement for Winnebago 2018 Replacement for Keystone Cougar 2011 Replacement for Tiffin Open Road 2015 Replacement for Montana Fifth Wheel 2007 Replacement for Keystone Sprinter 2019 Suitable for RVs, camping vehicle, travel trailers, and motorhomes Package List： 1 x RV Backflow Preventer Valve