This underarm protector is made from two layers of the strong nylon material. It is more puncture resistant than the cotton model and is made to protect your body from any blades that might pass through the jacket. The Underarm protector is worn over the dominant arm and is secured by an elastic strap that goes around the chest. It is built with safety and comfort in mind as it provides the best in both respects. Underarm protectors are required for competitions and recommended for use during bouting of any kind.