L.B. White Tradesman 170 Gas Forced Air Portable Heaters with gas control valve 

Put heat right where you need it with the Tradesman 170 Ultra propane forced-air heater. Start-up is easy with a dependable electronic ignition and time-tested design. With a variable rate valve and thermostatic control, save fuel and run optimally at 125,000 to 170,000 BTU per hour.