It uses a material called “Comfor Heat®,” which absorbs moisture, generates heat, and maintains the warmth. Its sweat-absorbing and fast-drying properties instantly wick away moisture and dry the fabric. This prevents stuffiness and chills caused by sweating, and maintains a dry, comfortable environment. It fits snugly against the body with a soft, gentle feel against your skin. Underwear for the severe cold of the winter season. It uses a material called “Wind Shell” on its front surface, which stretches well and has wind-breaking properties to block cold wind.