Alpha MJN45230C1 N-3B Doubleweave Parka. The n-3b doubleweave is our lightweight, wind and water resistant parka. Made with our performance fabric, this parka offers superior protection against the elements. The n-3b doubleweave has an adjustable hood as well as a button-and-loop closure storm flap. The alpha reflective details on the back shoulder and wrist are the perfect finishing touch. For a doubleweave flight jacket check out the l-2b skyray. The n-3b doubleweave has two zippered chest pockets and two snap-flap pockets with leather reinforcements. It features alphas signature zippered utility/pencil pocket on the sleeve. This parka has a doubleweave shell made from 93% polyester/7% spandex.