This is heavyweight like Ali-Frazier. Heavyweight like a left tackle on fourth and goal. This bottom is for hard-working guys who work in the trenches. The Carhartt 100643BT is made of 8-ounce, 95% polyester/5% spandex heavyweight knit, it’ll keep you warm. You’ll be happy to know that it wicks away sweat and fights odors. It has smooth flat-lock seams for the warmth and comfort you demand and an elastic waist. Goes great with our Base Force™ Super-Cold Weather Crewneck Top the way chili goes with fries.