This unit is simply two temperature thermostats on one box. It is an on/ off switching device, that can be used with a variety of heaters. It has two accurate dials calibrated in both Farenheit and Celcius. Ideal for controlling heat mats, and other low powered heaters up a maximum load of 300 watts on each heater. This thermostat is not suitable for controlling light bulbs. It is perfect for controlling two heaters independently. When a specific temperature gradient is required this is the unit to use. It will control two heaters with a maximum of 300 watts for each channel. This enables each heater to be set at a different temperature , even in the same terrarium. One channel can control the general background heat, whilst the other channel can control a "hot spot" to give the reptiles that essential temperature gradient that is so important to their husbandry. It can alternatively be used to control two seperate heaters in two seperate cages.