Aircraft Aluminum Defender Tactical Pen Military or Police Outdoor Survival Tool. Manganese steel pen holder: Accord with ergonomics design, easy to hook on your backpack, bags, notebook. The tactical self-defense pen is made of aviation aluminum. Features a click on-off cap Also could be used to break glasses in emergency. The pointed end of the pen body is NOT the writing end. The writing tip is housed under the cap on the blunt/flat end-cap.