This is the 4th Element Men's Xerotherm 3-Piece Set Drysuit Undergarment - Top, Leggings and Socks Features: 3-Piece Set: Top, Leggings and Socks Outstanding thermal performance Lightweight low bulk and buoyancy Extremely fast wicking Hardwearing Machine washable Performs when wet 53% Polyester / 38% Nylon / 9% Elastane The fastest wicking thermal baselayer on the market, tried and tested in some of the most extreme environments on the planet. The xerotherm is specified by the FBI and many other professional dive teams. The knit of the Xerotherm fabric produces the fastest wicking effect of any of the products in the fourth element product range. Moisture is drawn out through the fabric along fine fibres and then spreads out 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.