A thermostatic shower valve allows you to set the temperature at which you want the water delivered through the shower head and makes sure it stays at the set temperature within a half a degree. Many companies makes them.

Hi Amy,

Do you mean what brand? or what items in addition to the valve and trim? The benefit (as Carolyn mentioned) to the thermostatic valves (vs pressure-balanced) is that the temperature and pressure (flow) are not affected by each other.

As you probably know, a pressure-balanced valve on the other hand creates slower pressure with hotter water, and vice versa. Both will "balance" the hot and cold instantly if there's a sudden water flow change nearby (like a flushed toilet)

I use Hansgrohe thermostatic valves the majority of the time on my projects, because I've found them very reliable, and I like that they have an integrated waterproofing fabric surround. I also like that I can use a main head and hand-held etc without having to add any volume controls. Here's a photo of a project where I used one with three different fixtures controlled by the same main valve

Steve