I just spent the past month doing emergency rescue in Houston and southwest Florida. I routinely was having to break car windows if only to get into them and prep them for being towed out of the water. Some were fully submerged; others were just in water up to their door handles or so. We also had a number of large bundles dropped from helos that were bound in 2" nylon webbing and needed to be cut out of the webbing so they could be pulled out of the water and deployed. Well, I didn't find a glass breaker that worked, pretty much at all. It took a 1960s pickup with early non-safety glass in the side windows to break it with any of the little carbide-tip tools, whether a Leatherman or a classic rescue tool or whatever. If I needed to break the window, I needed a ball pein hammer of around 16 ounces. More weight made them hard to accelerate in close quarters (though for me, mostly breaking through from outside, that didn't really matter) but if I were using it underwater, extra weight was a handicap. Going much lighter meant it didn't do enough damage. On newer vehicles, most tools heavier than glass breakers still tended to bounce off until they finally put a hole in it, and the glass often would just crack and puncture at one point rather than disintegrate. Disappointing results. As for cutting webbing, the only thing that worked consistently was a coarse serrated blade. Hooks either worked once or twice and then dulled, or they snagged on any doubled-up areas (like around a buckle or d-ring), or they simply didn't cut to begin with. Wishful thinking. After doing about forty vehicle entries, in which half a dozen involved removing passengers, and cutting apart around three dozen dropped supply bundles, this was more than a lifetime of entry even for most EMTs. I wouldn't have wanted to be in a single one of those vehicles or held in by a single piece of that webbing. A serrated knife did the job on the webbing and for breaking a window in a car, I'd just have a ball pein hammer under the driver's seat.