The Carhartt Union Suit is a one-piece undergarment that keeps you warm, top and bottom. It's made of 100% comfortable, easy-breathing 8 oz. cotton and features reinforced stitching on all seams for long-wear. Buttons up the front from the fly to the neck and has a back opening with button closure. Both cuffs and ankles are rib-knit to help keep the cold out.