100% waterproof & windproof the Hamm Jacket is one hard-working rain jacket. Its polyurethane-coated, 100% nylon Helly Tech® Classic shell is wind- and waterproof. A nylon-mesh lining lets air circulate inside for cool, dry comfort. Light-fleece collar with drawstring adjustment. Velcro® storm flap over two-way front zipper. Multiple interior pockets. Articulated sleeves with Velcro® wrist tabs.