The N-3B is a Usaf Snorkel parka featuring reinforced elbow patches, a full-length storm flap and inset knit cuffs for durability and protection against the elements. The N-3B parka's nylon outer shell/polyester interlining ensures that no cold air seeps in. Our hood is lined and trimmed with synthetic fur, complete with adjustable draw cord/take-up strap. If you like a tight fit we recommend sizing down from your normal size.