The ULTRATHERM registered trademark originates from Demista Ltd, a Scottish company. The products which have been manufactured under this name in accordance with demanding European standards for more than 20 years rank among the most widely used vivarium heaters in the world. Thanks to the principle of infrared radiation, they create conditions which are very close to the natural environment of the animals kept. AZTEC has been part of the FENIX holding group since 2008 and our range of standard heating systems has thus been extended to include this specific range of goods.