Mr. Heater, MH200CVX, 200,000 BTU Convection Heater, Heats up to 5,000 sq ft., 75,000-200,000 BTU Convection Heater foruse with propane, Runs for up to 29 hours on 100lb propane tank, Piezo igniter, Thermo-electric safety valve shuts off gas flow if the flame ever goes out, Perfect for well ventilated construction sites, barns, warehouses and workshops.