Rothco Military ECWCS Generation III mid-weight underwear bottoms are level 2 of the Extreme Cold Weather Clothing System. These underwear bottoms are made of a 93% poly/7% spandex fiber which provides extra warmth in cooler climates. This fabric is a breathable, moisture wicking grid fleece with anit-microbial and anti-odor protection. Bottoms feature an elastic waist and leg bottoms, and an access fly. Available in colors Black and Coyote Brown. Sizes from Small to XXL.