Kubotan

A Kubotan is a weapon used in martial arts, specifically Saito Ninjitsu. Much like a pair of yawara, is a short bar, about 6 inches long (15 cm) and half an inch thick (1cm). It is made from hard plastic or aluminium, ribbed, and has a rounded tapered point at one end. It sometimes has a hole in the other end allowing it to hold keys or the like. Unlike a yawara (which is intended to break bones), kubotans are generally used to inflict pain without causing any physical danger to the target.