Updated for 2018 with new men’s and women’s fits. The ultimate baselayer for use under a drysuit. Made using Polartec Powerstretch originally developed for NASA, the Xerotherm traps a layer of air ? a much better insulator than water ? next to the skin, keeping the wearer drier and more comfortable. The range is designed to be worn under another undersuit or on its own under a neoprene drysuit.