K226 - M MW Cotton Union Suit Made of premium 8-ounce fabric, Carhartt's midweight cotton union suit delivers total body warmth in one comfortable garment. Its rib-knit neck and cuffs retain warmth, and seams are flat-lock stitched for added durability. For comfort and convenience, the fly and back opening feature button closures.*8-ounce, 100% cotton rib-knit fabric *Reinforced stitching *Back opening with button closure