The Wilkins Model ZW1017 Aqua-Gard Tempering Mixing Valve, when installed at the hot water source, is designed to mix hot and cold water in order to reduce the temperature of the hot water in the distribution system to 122?F(50?C) or less. The ZW1017's superior accuracy ensures safe water temperature from minimum to maximum flow rate. Further, multiple end configurations make this valve suitable for all residential and most light commercial installations. WARNING: This device should never be installed at the point of use where the end user could change its setting. Point of use device must be of the ASSE 1016 variety. It is recommended that the ZW1017 be installed with a shutt-off valve and thermometer in the tempered water line to provide accurate and safe water mixing temperatures, to be used in conjunction with ASSE 1016 device.