RV Vacuum Breaker Check Valve: fit for 571 Check valve,This check valve is a part of the black tank flushing system and installed between the freshwater inlet and the tank flusher. Designed to prevent backflow and back-siphonage, keeping your freshwater source clean and healthy. Upgraded Construction: Upgraded to brass material to withstand water pressure ranging from 8-125 PSI, this 571--CHK-A RV vacuum breaker check valve is built to last, proper water safety and long-lasting performance and peace of mind during your travels. Easy Installation: With 1/2Inch NPT male threads on both the inlet and outlet, this vacuum breaker check valve is simple to install in your RV's black tank flushing system, and must be installed a minimum of 6 inches above the highest point of any item connected to the waste tank where the flusher is installed. Versatile Application: Suitable for various RV models, campers, travel trailers, and motor homes, the 571--CHK-A RV tank flush one way check valve is a reliable replacement for cracked or leaking check valves, ensuring efficient water flow. Reliable and Efficient: Direct replacement for cracked and leaking rv vacuum breaker check valve, if your rv check valve was leaking when flushing black tank, or when black tank flush line system was blocked/faulty and wet rv trailer floor. Upgrade the RV vacuum breaker check valve and say goodbye to leaks and contaminated water. Colour:As Shown Material:Brass + Aluminum Package Contents: 1 x RV Vacuum Breaker Check Valve Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.