This series of TEC (Thermoelectric Cooler) modules, ATE1-TC-71, has 71 pairs of Peltier elements inside with a maximum voltage of 9.0 Volt. They are designed for temperature cycling applications, in which a TEC module is exposed to demanding physical stresses as the module shifts from heating to cooling, and this can significantly reduce the operational life of a standard TEC. This thermal cycling TECs have significantly longer thermal cycling operational life than standard TECs. In the part number, for example, ATE1-TC-71-5R5AS, “TC” stands for thermal cycling; “5R5A” indicates the maximum current allowed for entering the TEC module is 5.5A; “S” represents sealed version. Without this “S” suffix means non-sealed version.