General Leathercraft Leather Head Gear - Barbell Flex This is the ultimate General Leathercraft Leather Head Gear on the market today! This one size fits all leather neck harness is used to strengthen the neck and upper back muscles. It is made of 1 3/4″ genuine leather and neoprene lining for comfort. It features heavy duty " D" rings, a 23″ chain, nickel plated steel rivets, 6mm steel ...