Double Walled Consturction. Automatic boil/warm function. Great for catering. Great for shabbat. 110 volt for North America. This double walled stainless steel urn is perfect shabbat. After the water quickly comes to boil, the unit will automatically go to a keep warm function. Having both a double walled construction and the keep warm function allows for the water to stay hot without using a lot of energy. The urn can also be used for catering purposes. 110 volt for North America.