Mr. Heater, 125,000 BTU Forced Air Propane with Quiet Burner Technology, Heats approximately 3,000 sq ft., 125,000 BTU per hour, For use with propane gas, Runs up to 11 hrs on 40 lb tank (low setting), High temperature limit switch, Continuous ignition, QBT Technology - 50% Quieter than a standard propane heater, Perfect for well ventilated construction sites, barns, warehouses and workshops.