The Uzi Tactical Pen from ThinkGeek is constructed of aircraft-grade aluminum, accepts standard Parker and Fisher Space Pen refills, and has a “razor sharp tactical DNA catcher crown that you can use for self defense and come away with your attacker’s DNA.” Video after the break.

The crown also doubles as a glass breaker if you ever get trapped in your vehicle. This badass writing utensil is made of high-grade aircraft aluminum and writes upside down or under water.

[via ThinkGeek]