Heatcraft Refrigeration 21340101 Defrost Timer is a control component designed for compatible commercial refrigeration equipment, including walk-in coolers and freezers. It automatically manages defrost cycles by activating the refrigeration system and defrost operation at predetermined intervals, helping prevent excessive ice buildup on the evaporator coil. Proper defrost control mai... https://www.partshnc.com/21340101-heatcraft-refrigeration-defrost-timer