Hongso Magnetic Thermostat Switch for fireplace stove fan/fireplace blower kit Magnetic Thermostat Switch for Fireplace Stove Blower Fan / Kit use, no screws and nuts needed Temperature switch closes (turn on) at approximately 120F and opens (shut off) at approximately 90F (+/- 5F tolerance) Measures 2 1/2-inches in length by 1-3/4-inches in width,2-year limit warranty. Strong magnet! Easy and simple to place! Perfect for fireplace blower and fan kit applications NOTE:Blower will not start until thermodisc is heated to approximately 120 F.