Surefire x300u-a - SureFire X300 Ultra LED Weapon Light

The Surefire x300U-A is an exceedingly well-manufactured weapon light. The quality of the beam (color and flood) is excellent. It has a momentary on-off switch and ambidexterous on-off controls, which are ergonomically placed. My main concern was whether the fit on the rail of my Glock 10mm (Glock 20 standard) Gen 4 pistol would fit correctly without jury-rigging it with electrical tape. I'd seen videos of the excessive wobble that some Glock owners have experienced, and I didn't want that wobble in a $300 weapon light. For $300 the light should snap into place and have no wiggle, whatsoever. For instance, the 9mm Glock 17 supposedely has no wobble, whereas the Glock 19 (also 9mm) has a terrible wobble - according to the video reviews that I saw. Well, there really is no way to know for sure unless you buy it and install it. I can tell you, for absolute certain, that the Glock 20 Gen 4 (which is the large-frame version of the Glock 10mm, and which is similar to the difference between the Glock 17 (large frame) vs the Glock 19 smaller frame) is a perfect fit. No wobble whatsoever. It slides on, snaps into place and fits like a glove, right out of the box with any mods. Other than the fit, the quality is excellent - durable and very well-designed. For me it was an easy decision. I bought the Surefire x300U-A over the Streamlight and O-light brands and happy I did so. If you have a Glock 10mm Gen 4 (Glock 20 with built-in rail) then don't hestitate to buy the X300U-A model. For the polymer-built Glock you're much better off with the x300U-A than the x300U-B or other options, which are intended for a metal frame pistol. Besides, the slide onto the rail option without having to mess around with over-tightening a thumbscrew or making it a permanent installation is the far better option.