Mr. Heater, MH175QFAVT,170,000 BTU Forced Air Propane with Quiet Burner Technology, Heats approximately 4,000 sq ft., 170,000 BTU per hour, For use with propane gas, Runs up to 17 hrs on 100 lb tank (low setting), High temperature limit switch, Automatic solid state ignition, QBT Technology - 50% Quieter than a standard propane heater, Plugs into a 110v outlet, Perfect for well ventilated construction sites, barns, warehouses and workshops.