A concealed diverter is simply a built-in valve that is concealed behind the tiling in a shower enclosure. The only visible part of a concealed shower valve is the chrome control plate and handles; the rest sits neatly out of sight within the wall. A shower diverter performs two basic functions, it controls the temperature and the flow of the water in your shower. A 2-way diverter supplies water to two separate outlets by allowing switching between the two, only one can be on at a time. A three way outlet supplies three shower functions/outlets.