Walls Men's Big Zero-Zone Waco Insulated Muscle Back Jacket 100% Cotton Imported Machine Wash Walls muscle back technology uses a large band of elastic across the back to increase your range of movement, four-piece sleeves with articulated elbow patch Comfort rib-knit waistband and cuffs Two large front patch pockets and inner utility pocket with hook-and-loop closure Signature front metal zipper with pull Three-piece hood with locking drawstrings