Partstock(TM) 2-Pack Aircraft Aluminum Defender Tactical Pen Military or Police Outdoor Survival Tool.(Black) The tactical self-defense pen is made of aviation aluminum. Accord with ergonomics design, easy to hook on your backpack, bags, notebook. Provide nice writing tools with high performance and bodyguard for emergency. Also could be used to break glass in emergency. Diamond thread design at the handle, excellent anti-skid ability.