Portable Gas Torpedo Heater Fuel Type Natural Gas Heating Capacity Output 155 000 BtuH Heating Area 3 500 sq ft Minimum Cylinder Size 100 lb Ignition Type Direct Spark Ignition Power Source Electric Thermostat Included Unit-Mounted Overall Height 16 in Overall Width 9 1/2 in Overall Depth 24 in Automatic Safety Shut-Off Included Yes Built-In Air Pressure Gauge Included Yes Digital Temperature Readout Included No Flame-Out Sensor Included Yes LED Diagnostics Included No