The digital heat mat thermostat allows you to select and maintain precise, optimum rooting temperatures for faster and more successful seed germination and seedling growth. The unit automatically monitors and adjusts heat mat temperature by reading the actual soil temperature through the attached soil probe. Your seedlings stay at a constant temperature without fluctuations that can affect germination and damage young seedlings. Easy to read large controls display temperatures in your choice of Celsius or Fahrenheit. Fully adjustable temperature range from 68 degrees F to 108 degrees F (2 degrees C to 42 degrees C) . Works with all our seedling heat mats.