The J41 is a jacket / sweat shirt / wetsuit hybrid with a unique dual zip system. There is a drop-in zip for pullover donning and doffing. Escape Zip for rapid vehicular exits. Holster pockets, zip lanyard garage, and adjustable / zippable cuffs are use driven details that bring balance to a design leaning to the far edge of forward. The technology indcludes Gore-Tex® microfiber fabric with Paclite® product technology and I love it. Both design and function are in compete harmony.