Stay warm in cold weather climates with Rothcoâ€™s ECWCS Poly Zip Collar Shirts. As the mid-layer for the 3rd generation Extended Cold Weather Clothing System, the cold weather shirt is constructed of polyester material and offers optimal warmth with the soft and comfortable fleece lining. The ECWCS military shirt features zippered collars that can be fully zipped like a turtleneck or unzipped too cool you off in case you are too warm. Retain body heat with the elastic wrist cuffs, as they will fit comfortably and wonâ€™t allow air to travel up your sleeves. Whether you are in the armed forces, going skiing/snowboarding or working outside, Rothcoâ€™s poly zip collar shirt is the perfect lightweight undershirt to keep you warm in the most extreme outdoor conditions.