Review on Phoenix Faucets PF223541 Catalina Rubbed Bronze Two-Handle 4-Inch Shower Valve with Vacuum Breaker by Donald Vargas

I installed this bevel in my camper shower. The old edge was a cheap block of plastic, and the pipe that mixed hot and cold water was cracked. I bought this one thinking it would be mostly metal but it isn't. Only the handles and outer casing were metal. All internal parts were still made of plastic. Went ahead and installed this and it works great. I'm not crazy about the backflow feature. I think if you shut off the water at the edge wouldn't that prevent the water from flowing back into your fresh water tank?