Thick Skin Union Suit: AKA “The United Front” The IR union suit is a unique one-piece cold weather base layer made with soft, heavyweight, stretchy, double sided polyester fleece. An innovative super stretch neoprene collar allows you to enter the suit via the neck opening, thus no zippers or closures. Mens union suits feature a front fly. Perfect under a dry suit or as a base layer for any outdoor pursuit in cold weather. For theses reasons, we are naming this union suit as our 2015 best layering piece for cold weather paddling!