Isoguard is a base layer for cold to very cold weather. The Isoguard line uses a 215 gsm fabric. The fabric consists of 96% polyester and 4% spandex. All Isoguard styles are a 4 way stretch design. The form fitting construction allows for maximum warmth retention and easy movement during high level physical activities. The french terry construction facilitates moisture transfer from the inside to the outer layer of the garment. The Isoguard line utilizes a moisture management wicking construction that makes each garment quick drying.