In the upper body icebreaker use their merinoloft insulation which provides a warm breathable and natural alternative to synthetic insulations with a 100 recycled polyester face fabric in lower body arms and lining the ellipse features a super soft and quick drying merino and polyester jersey waffle fabric that actively manage moisture during cold high output days in the mountains or out on the trails zippered hand pockets and an internal stash pocket secure all your small daily essent