Keep your items cool, or warm, while on the go! The Dometic TC-21US thermoelectric cooler is perfect for maintaining the temperature you need.┬áAll you have to do is plug it in a 12 volt DC or 120 volt AC outlet to keep your items at the temperature you want. Forget about dealing with ice again. Designed to make your life easier. As soon as the power is on, it cool at full capacity to reach the desired temperature - down to 40 degrees F below ambient temperature.Once this has been achieved, the TC-21US switches automatically to the power-save mode for constant cooling.