Maglite's 4 D-cell flashlight spits out around 120 lumens of brightness. The mammoth LED Lenser X21 shoots out 1,200. It's blindingly bright. It lights up entire rooms on its own. It will hurt your eyes. A lot.
Why do you buy a flashlight? To light things up. The X21 is almost too bright. It's extremely visible even in a well-lit room, or outside—photos do it no justice. And because it uses electricity-friendly LEDs, it can beam brilliantly for a long, long time—at its max power mode, we've far surpassed LED Lenser's advertised 2.5 hours. We'll take their word on the 25 hours of 225-lumen low power mode. The thing's also brutally substantial; if you want a flashlight you can drop repeatedly and also bludgeon someone to death with, this is tops.
The X21's very heavy: 3.25 pounds. This might wear on your wrist if you had to use it for extended periods. But the X21's only real design flaw is the stubborn push motion required to switch the light's lens and mirror mechanism between a focused and diffuse beam. A twisting control would have been much better, or something that didn't require jerky motions.
This is the ultimate emergency flashlight. For reading, it's overkill. But for power outages, wilderness wanderings, or anything dark that needs to be bright as a trillion dollar casino, the X21 is a stellar pick.
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