Slip into something Carhartt tough. The Carhartt 100644BT Base Force™ Super-Cold Weather Crewneck Top is made of 8-ounce, 95% polyester/5% spandex knit and it keeps the sweat down and fights odors. It has smooth flat-lock seams for comfort. Rib-knit cuffs and the crewneck keep in warmth, which this top is all about. A drop tail covers your butt. This is the wing man to the Base Force™ Super-Cold Weather Bottom. They go together like Sunday and football.