WHD-E-CU Capillary Temperature Controller Copper Adjustable WHD-E copper adjustable copper capillary thermostat is a mechanical temperature regulating device used for precise temperature control in heating systems. It employs a copper capillary and copper bulb with a liquid sensitive to temperature changes in the environment or surface temperature. When the liquid expands or contracts due to temperature fluctuations, it triggers a mechanical switch, thereby connecting or disconnecting the circuit. WHD-E thermostat has a variable temperature range and users can set the desired temperature threshold according to specific application requirements. This flexibility makes it suitable for various heating devices, especially water heaters with a temperature range of 75°C (70°C/72°C/73°C). https://www.wzleh.com/product/heating-thermostat/