High Efficiency 2000 Watt Resistored Heating Element..Specially Formulated Glass Lining Prevents Corrosion and Extends the Life of the Tank. Automatic Thermostat keeps Water at Desired Temperature. Meets or Exceeds National Appliance Energy Conservation Act Requirements. Over-Temperature Protector Cuts Off Power in Excess Temperature Situations. U.L. Listed and Complies with Underwriters Laboratories Specifications 174. 6 year. 40 gallon capacity. Tank height 31-1/2. Tank diameter 24-1/4.