If you carry a full size flashlight like the Streamlight 20X LED, 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 from the old cap and put on your new Bust a cap to insure that your light remains water tight.
WARNING: This product may contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov