Essential Apparel Men's Waffle Knit Heavyweight Thermal Long Underwear Union Suit - Red 100% Cotton Heavyweight Unionsuit provides insulation and wamth Easy-open backflap with button closure, Tagless Soft Waffle knit thermal fabric will trap warmth even during low activity Anti-Microbial for freshness, Comfortable rib knit cuffs Flat seams construction for comfort and durability