The two sections of the weapon are commonly made out of wood, while the link is a cord or a metal chain. The nunchaku is most widely used in martial arts such as karate, and is used as a training weapon, since it allows the development of quicker hand movements and improves posture. Modern-day nunchaku can be made from metal, wood, plastic or fibreglass. Toy and replica versions made of polystyrene foam or plastic are also available. Possession of this weapon is illegal in some countries, except for use in professional martial art schools.