Hydrofarm's electronic temperature controller is compatible with all heat mats and is an optional accessory for Hydrofarm Seedling Heat Mats. The thermostat controls the temperature of heat mats evenly in colder or warmer than normal environments. It provides constant optimum temperatures for specific plants. Easy plug-in operation with illuminated indicator light and three-prong ground plug. Digital temperature controller for heat mats. Provides constant optimum temperatures for specific crops. Controls temperature in colder or warmer environments. Illuminated indicator light; 3-prong ground plug. Compatible with all heat mats; optional for Hydrofarm Seedling Heat Mats. Controllable range from 68 to 108 degrees Fahrenheit. Celsius or Fahrenheit read-out