GTFO - Rescue Glass Breaker - Tungsten Carbide Wrist Tool by Shomer TEC

This is such a simple safety device and novel idea that I had to do a double take. I have a glass breaker in my 4x4 as you never know when your ambition exceeds your ability and end up the wrong way up in a ditch and need to get out quick. Well now, if you wear one then it'll be in any car you are in. 

The GTFO Rescue Glass Breaker is a vital emergency tool designed for breaking vehicle windows in critical situations, such as escaping a vehicle or rescuing others. Its versatile application makes it a must-have safety device, but it is strictly intended for adult use or use under adult supervision. This is not a toy—it’s a high-performance tool built with a durable shock cord on a double-slit knot bracelet for added strength.

It is a discreet, wearable escape tool capable of instantly destroying tempered glass with the Ballistic-Striker-Bead. The hardness of the bead (Hv30 1750) exceeds even the core hardness of armour-piercing ammunition so it is rather tough.

You only need a tiny amount (1.2g) to deliver sufficient impact to destroy tempered glass on the first strike making it an invaluable tool in the event of a car accident.