Allows you to determine at what air temperature AND time of day the de-icer turns on by using both an air temperature controller and timer clock.Time function sets de-icer operation duration, and temperature sensor starts the de-icer only when temperature falls below the set threshold. Both settings are user controlled. Easy to install and operate.Kascos C-20 Time and Temperature De-icer Control is designed and engineered exclusively for outdoor use to operate your Kasco De-icer with maximum energy conservation. The C-20 will only operate your Kasco De-icer when both the timer and thermostat are activated. Designed for use with Kasco 120V AC De-Icers.Important: The C-20 is designed to operate only one Kasco De-icer. Daily observation is required for all de-icing installations. Any electrical equipment should be plugged into a GFCI-protected outlet or circuit for safety, especially in water. It is never a good idea to be in the water with electrical equipment in operation or even plugged in. Also, make sure to test the GFCI breaker in the circuit once a month to ensure proper operation.C-20 Owner's Manual