Sorry gang, I have to break with the crowd on this one. I tried this in my Fenix HL 55 head lamp. It does not run the headlamp for the specificed duration. Not even close. Spec is 3 hours 45 minutes @ 420 lumens. This battery ran the HL 55 less than two hours. Olight and Fenix batteries with lesser capacity run the light to spec and even a bit longer. I would not recommend this battery.

Well built, charges good, very happy.

Well made battery

I recently purchased a high capacity pocket variable output and function flashlight from Battery Junction and found that it malfunctioned immediately on standard rechargeable 18650's. I sent the flashlight back and learned that I missed the notice that this unit requires high capacity, high amp 18650's. I purchased several of the recommended brand and, although the problem was slightly improved, these too failed to allow the flashlight to perform properly. So, I tried one more time with several Klarus 18GT'S and the problem not only disappeared but the flashlight has continued to now work flawlessly for an extended period much longer than I expected. I have several types of high capacity flashlights and spots using 18650's. I'll soon be replacing all the older batteries and spares for these units with the Klarus 18GT's. Well worth it.

This is a really good battery not sure of how long it will last. Time will tell