Nick Kaumans (Albuquerque, NM)
Having used a standard 21 inch foam 4140 ASP baton against a window recently. I can attest to how difficult it is to break. There was an emergency and I stuck the glass over 15 times with no break. I then turned to handle side and struck three times before breaking through. When the baton broke through, it damaged the foam grip and steel cap. As you can see below. This was proof enough for me I needed a window breaking cap. I replaced the baton with another 21 inch electro ess and went with as ASP brand window breaker as your standard cap covers it when it's not in use. On bust a cap a sharp point is always present. In addition, while the foam is tough, it was apparent glass shredded into and remained in the foam handle, so this time I purchased the WaveMaster grip that is much more resistant to damage.
Working with a tow yard I asked if I could test the cap on a window, it was a junker car and they said sure. The window very easily busted with a light strike.
However, the ASP cap is made from aluminum not steel like bust a cap. It features 3 ceramic pins providing better angles for the strike but damage can easily occur to the handle foam and a high amount of damage for the cap. The glass was hard enough to damage the threads of the window breaker. Pictures below. This is why I chose the wavemaster handle, minimum damage to the grip, but the cap took a beating... If it had been a foam handle it would have to have been replaced.
Image of ASP baton breaking through a car side window via the handle: http://img607.imageshack.us/img607/3605/3msp.png
Below is one image showing the 21 inch eletroless with an ASP window breaker, it also shows the damage from one use. ASP should have made the material from steel like bust a cap, at the same time though it leaves the sharp point exposed.