Features . 84 Thermal efficiency. ASME code brass headers. Built with heavy-duty commercial grade materials. Natural gas or propane and hi altitude models. Meets ASME Low Nox requirements. Unitherm Governor anti-condensation control. Protective wire harness to prevent rodent damage. 336 000 BTU Electronic LP Heater - Cupro - Nickel. Dimension - 44 x 31 x 30.25 in.