Ventamatic XXFIRESTAT 10-Amp Adjustable Programmable Thermostat with Firestat for Power Attic Ventilators, Replacement Thermostat FIRESTAT THERMOSTAT: The Ventamatic Firestat Thermostat controls power attic ventilators. The Firestat Temperature Range is 183F at which point it cuts off the appliance. ADJUSTABLE THERMOSTAT: The Thermostat is adjustable by the use with a simple screw driver adjustment. It has adjustable bi-metallic switch. ENERGY EFFICIENT POWER ATTIC VENTILATOR: It provides energy-efficient operation of power attic ventilators and the temperature ranges from 50F to 120F. REPLACEMENT THERMOSTAT: This Ventamatic Replacement Thermostat controls power attic ventilators to promote the equalization of temperatures inside and outside your attic. Firestat safety feature shuts fan off at 183F Controls up to three units, not to exceed 10 amps. PROGRAMMABLE THERMOSTAT WARRANTY: This thermostat provides 10 years of warranty. It is of opening size 4.8 x 2.5 x 4.8 inches