The UMV500-LF/U Series Universal UnderSink Thermostatic Mixing Valve is intended for use in under counter and under sink applications. The UMV500-LF/U Universal Model is designed to be used as a three port design (touchless sink) or a four port design (two handle sink) with the addition of the 4 port adaptor (supplied with UMV500-LF/U). The UMV500-LF/U is used to prevent accidental scalding. The outlet water temperature must be properly adjusted by the installer using a thermometer to measure the outlet temperature at the faucet. A maximum outlet temperature of 110 deg F (43 deg C) is recommended.