Temperature Controller - Thermostat keeps temperature steady for optimum health Safety feature guards against overheating Controls any type of heating device (sold separately) Peace of mind for owners of cold-blooded pets Proper terrarium temperature is recommended for a reptile or amphibian's healthy, active life. Add a Temperature Controller to maintain a pet's terrarium at any preset temperature between 60° and 105°F. Simply place the temperature probe in a terrarium using the included suction cup, then connect any type of incandescent heat source (heating device is not included). An added safety feature automatically shuts off the heating system if terrarium temperature exceeds 110°F due to heater malfunction or excessive sunlight. Choose from two types: a 500 watt system with a single input or a three-outlet device that can manage 1000 watts of heating power.