Kubotan

thingiverse

The Kuboton, commonly misspelled as Kubaton or Kobutan, is a trademarked self-defense tool crafted by Takayuki Kubota back in the 1960s. Typically, it measures no more than 5.5 inches in length and half an inch in diameter, comparable to the size of a typical pen. Its hard plastic material is usually high-impact, such as Lexan. Six evenly spaced round grooves run along the Kuboton's body, paired with a swivel or split ring attachment at one end for holding keys securely. The untrained eye may see it as just an ordinary keychain fob, but it can be viewed differently by some authorities as an aggressive weapon due to its design and appearance.