check valve on water outlet for shower?
We are putting in a new bathroom and I am buying the various parts to put together a shower system. It will have a wallbar with handshower, and an overhead rain shower. My question is, do I need a wall outlet with a check valve? Hansgrohe sells one with and one without - they both look exactly the same in the picture. They also sell one that has a vacuum breaker. Which do I need? Any help would be great - I'm no plumber!