Hazardous Area Drum Heaters safely heat flammable liquids in steel drums. Quality silicone rubber and fiberglass construction is moisture proof for durable long life. Simple spring and hook fastener for easy installation and removal. Thermostat assembly has 10 ft. cord w/NEMA 5-15 plug. High limit cut-off limits band temperature to 80% of "T" rating, the auto-ignition temperature of the flammable product, as referred to in National Electrical Code Article 501. Specify "T" rating when ordering(T3 or T4A). T3 allows surface temperature up to 292° F. T4A allows surface temperature up to 158° F. These heaters operate on 120 volts AC and are available as 240 volt AC. Hazardous heaters are also available for 30 gallon steel drums as 120 volt and 240 volt AC .