One of the most affordable lights that both first responders and civilians carry is the Maglite (Maglight). If you carry a full-size flashlight, like the Maglite (rechargeable or D-cell), the cap alone will not break glass. 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 (Maglight) that takes "D-Cell" batteries and rechargeable.