Thermostat Only for Super Sprouter Seedling Heat Mat. This easy to use matt lays underneath your propagation trays, slightly warming them and providing ambient, ideal temperature for your sensitive cuttings and seedlings. This reliable thermostat ensures that your starter soil/medium reaches the ideal temperature for germination. It also allows the user to closely control the mat temperature using an easy dial. Get started by simply plugging the mat into the thermostat then place the temperature probe into your soil or other growing media. 120 volt grounded plug. This thermostat will help you achieve the perfect temperature to get your cutting/seedlings started on the right track.