Soft, long-sleeved undershirt with collar. The undershirt has a close fit and a longer back for optimum function. High neck with zipper. The sleeves have a thumb hole so they can be pulled down over the hands to protect against draughts. The undershirt is made from two fabrics: one has good insulating properties, while the other is thinner and placed where you sweat most, ensuring that perspiration is wicked away from the body.