Architecturally inspired and awe inspiring. This thermostat trim kit is part of our minimalist Times Square Collection. When installed with a thermostatic mixing valve (sold separately), you select the water temperature with the lower handle and operate the on/off volume control with the top handle. Once set, the temperature remains constant.Brass Casting: Highest quality faucet material for durability & long life.Wax Thermostatic Unit: Permits shuttle valve to move between the hot and cold seat to maintain the pre-selected constant water temperature.Back to Back Capable: Hot and cold can be reversed.Spring-Loaded Check Valves: When the hot and cold waterenters the fitting, both supplies pass through the spring-loaded check valves to prevent cross flow of hot and cold water.Integrated Stop Valves: Ensure easy cleaning and servicing.Adjustable Hot Limit Safety Stop: Limits the amount of hot water allowed to mix with cold. Reduces the risk of accidental scalding. Maximum water temperature limit may be reduced to 104 or 109 degrees Fahrenheit.