Reliable, warm mid-weight base layer ECWCS Gen III Level II Underwear Crew Top keeps your body heat in and the effects of extreme cold weather out. This thermal shirt is made of breathable materials that are designed to retain your body heat and wick away moisture for a base layer that keeps you warm and dry. Antimicrobial and odor-defending technology makes this the ideal undershirt for those who spend a lot of time outdoors in cold climates. With thumbholes in the sleeves to ensure a seamless seal between the sleeves and your gloves, this thermal shirt will keep you warm for many winters to come.