WarmWool Longs is Aclimas most popular long underwear. The fit is snug and the garment is perfect as a first next-to-skin layer on cold days for all types of activities. The elastic waist has wool on the inside for best comfort. You do know that wool warms when wet? WarmWool is a knitted material and thus elastic and flexible. The fabric is made of 100% merino wool, with a weight of 200gsm. The fibres in WarmWool are 20.5 microns, the fabric is soft and comfortable against the skin. WarmWool is suitable as a next-to-skin layer or second layer when it gets really cold.  Materials100% Merino wool