The Fourth Element Xerotherm Leggings is an ultimate baselayer pants 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 knit of the Xerotherm fabric produces the fastest wicking effect of any of the products in the Fourth Element range. Moisture is drawn through the fabric along fine fibres and then spreads over the outer surface. This maintains a thin layer of air next to the skin. This is so effective in the Xerotherm that some wearers report experiencing minor suit leaks during the dive without even noticing until after the dive. The range is designed to be worn under another undersuit or on its own under a neoprene drysuit.The Fourth Element Xerotherm Leggings have been designed for maximum performance. The high waistband ensures good overlap of the top and leggings and the unique foot pocket design ensures the leggings do not ride up. Flat seams provide next-to-skin comfort throughout the dive. Xerotherm Leggings features Outstanding thermal performance Lightweight Low bulk and buoyancy Extremely fast wicking Hardwearing Machine washable Performs when wet "The performance is superb". This was the reaction of Doug Allan, world-renowned and award-winning underwater filmmaker and author, after testing the Xerotherm in -2 degree (29F) water inside the Arctic Circle in Svalbard, whilst shooting sequences for the BBC production The Blue Planet. Fourth Element Xerotherm Leggings - Women's - DirDirect