Funny you should ask...When I found out how much it was going to cost to have it replaced, I put it back in the truck and now I can't find it. How unlike me!! It is white plastic, turns 1/4 turn to drain, has a mounting flange, all one piece, with two holes in it. There are threads on the back side of the flange that screw into something invisible to the naked eye. There were two sheet metal screws through the holes, threaded into the fresh water tank. Between the tank and the flange is a small sheet metal bracket that looks as if it was meant to protect the valve, but failed. Are you getting the idea that I am not a technical writer?
Thank you all for any help, Jim