The greatest advantage our Tactical pen employs is the ability to break glass. Even tempered glass like your windshield. In the event that you need to break out a windshield, deploy the glass breaker tip with a half turn. Wrap a shirt, or jacket around your hand leaving the tip exposed for action. With a backhand motion, aiming squarely for the middle of the windshield, thrust the pen into the glass with force. If you are doing this in a real life event, make sure that you commit the action fully. In a submerged vehicle, the pressure from the incoming water will be intense, combined with the glass.