The CH-555-25W Thermostatic Cabinet Heater is a heat source and thermostat in one package. It is designed to operate in instrument enclosures in Class 1, Div 2 rated locations. It will generate about 28Watts at 120 Vac. The set point is fixed at 0 C. It runs on single phase power from 90 Vac to 130 Vac. The standard heat sink is formed from rugged 0.1" aluminum. Custom heat sinks can be created.