Portable Gas Torpedo Heater Fuel Type Natural Gas Propane Heating Capacity Output 400 000 BtuH Heating Area 20 000 sq ft Minimum Cylinder Size 2 000 lb Ignition Type Direct Spark Ignition Power Source Electric Thermostat Included Unit-Mounted Overall Height 24 in Overall Width 18 in Overall Depth 46 in Automatic Safety Shut-Off Included Yes Built-In Air Pressure Gauge Included No Digital Temperature Readout Included No Flame-Out Sensor Included Yes LED Diagnostics Included No