The following are images on one of the jobs we did. It shows how we convert a old two handle or three handle tub/shower valve into a modern single handle tub/shower valve that is also pressure and temperature balanced. In other words if you have a old house that when you flush the toilet or run water else where when someone is in the shower; the water temperature and the pressure with the new single handle valve will not change like it does with older two or three handle tub/shower valves. Changing to the single handle from a two or three handle valve is doable for most all tub/showers. The process requires access to the inside of the rear or the wall behind the valve. If in a closet we can install a "access" panel that has a flush finish as the end result. Fill free to call with any questions.