Stainless Steel Tank - The open storage tank in high quality stainless steel 304 guarantees crystal clear drinking water.Tropicalized - Specially designed for countries with hot climate to cope with these extreme climate the copper tubing round the tank is covered with an aluminum conductive compound for better heat transfer.Copper Tube - The copper tube around the tank is flattened so that the surface of the tube touching the water tank is increased by 70%. Also, Conductive Aluminum paste is placed in between the tube and the surface of the tankwater cooler, is a machine that cools or heats up and dispenses water with a refrigeration unit.