Many of the lights that Surefire makes these days offer multiple levels of output. This can be a great option for a light that is going to see general use since it allows the user to tailor the amount of light to the task at hand. However, it is not necessarily best for a weapon light. When you turn on your weapon light, you want lots and lots of light… right now.
The VTAC Mini-L4 is a compact, single CR123 battery powered light that has one output level (110 lumens) and a focused beam that allows it to provide usable light at extended distances. When you turn it on, you get bright white light. There is no chance of accidentally entering a lower output mode.
The VTAC Mini-L4 is available by itself or as part of a package with the excellent VTAC Light Mount. The combo makes a great alternative to the Surefire M300 Scout.