Turn on the turn-of-the-century charm. This thermostat trim kit is part of our traditional Portsmouth® Collection. When installed with a thermostatic mixing valve (sold separately), you select the water temperature with the lever handle and operate the on/off volume control with the cross handle. Once set, the temperature remains constant.Old World charm and traditional craftsmanship radiate throughout the water efficient Portsmouth™ bathroom collection from American Standard®. To achieve its turn-of-the-century authenticity, each design facet – from the symbolic Portsmouth cross handle to the vintage spout detail – has been carefully crafted to reflect an intricate and iconic period piece. Metal wall escutcheon Metal handles Less valve For use with R520 and R540 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 water enters 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.