One of the most affordable lights that both first responders and civilians carry is the Maglite. If you carry a flashlight, like the Mini Maglite (AA batteries), the cap alone will not break glass (see our videos).
There is no way you can break a window with these flashlights without causing damage to your expensive light or injuring someone from flying glass. Attaching Bust A Cap® to your flashlight will insure that it will break glass with just one tap and not damage your equipment.
Warning: Please remove the o-rings and spring from the old cap and put on your new Bust A Cap to insure that your light remains water tight.
Note: This is for the Maglite that takes "AA" batteries.