The Mopeka Tank Heaters are electrical wrap heaters (120V) designed to fit your DOT cylinder. With a temperature dial up to 60C, you can adjust as needed for your current weather conditions. When vaporization is a problem on a cold, winter night, the Mopeka Tank Heater ensures no flame outs on all your appliances. This model is for 40 lb tanks. Dimensions are (inches) 38.5L x 8.7H. UL, CE, and RoHS certified.