Excellent product. Well built, easy to operate, unbelievable light output.

Light works great. Super bright on turbo. Would like a little more throw. Parabolic reflector is almost non-existent so throw even at 4000 lumens isn't real far. Controls are horrible and light gets too hot to touch bezel after a few seconds on turbo. Battery lasts forever. Bought a second battery but never used it yet. Not a bad light but not the greatest either.

Real nice light fast free shipping thank you

I was not satisfied with this flashlight from day one, but rather than pay($24) for the shipping and restocking fee I kept it. The biggest issues that I have are: 1. In order to charge this light the battery must be removed and plugged into charger. 2. If you leave the battery unused in the light for more than a week it will be completely discharged(normal according to customer service). 3. The Turbo 4400 lumen setting will only stay on for 20 seconds before it lowers itself down to the next brightness. I have better flashlights that are nearly as bright as this one, that I paid less than half of what this cost me.

3.5 stars. It's a good light, does all it claims, seems very well made, packs a lot of bright into a compact light, and all control is via the side switch. (Bias alert: I hate tail switch lights.) But it doesn't replace the Nitecore MH10 as my all time favorite, for several reasons. A minor one is that the brightness selection seems very sensitive; that may just be a matter of the light training me more, but after some weeks I still bump the level unintentionally. The other is no USB charging circuit in the flash. That's clear in the description, I knew when I ordered it, and it comes with a battery (21700) that has a USB-C charging circuit built in. But after using it for a while now, I have two issues. One is convenience - with the MH10 I could plug it in when I got back to my desk, and it took only a couple of seconds to unplug and be on my way later with a topped-off battery. With the E4K, not as easy or fast. Got to open it up, take the battery out, plug it in, then put it back in and close it up. The other: if the charging circuit in a light goes out, I can still use it by charging the batteries externally - less convenient, but it works. But if the charging circuit in this battery, which is not cheap, goes out, can it be charged in an external Li-ion charger, or do I have an expensive paperweight, even if the rest of the battery is good? I don't know about the 21700, but I know from sad experience that's the case with some other built-in-USB-charger Li-ion cells I use.