Burton Spas are fully insulated. The polyethylene shell is extremely U.V. resistant and will last a lifetime. The total dry weight of the spa is only around 400 pounds making it very portable. Although almost seven feet across, this 275 gallon four person spa will operate very economically on 110 or 220 volts. Also, the one piece seamless construction of a Burton Spa will not allow unwanted guests such as mice to take up residence in your spa.