The classic piece of thermal underwear that can help keep you warm this winter. Built for comfort and for warmth, the union suit is functional and perfect for any winter activity. Indera Mills Men's Unionsuit Model: 865 Color: Red 5.5-ounce, 100% cotton thermal unionsuit Smooth 1x1 rib knit fabric Full cut one-piece for comfort Full button front with one-button vertical flap seat Rated for cold temperatures Sizes: Small through XXL