Rechargeable Battery 3.7V 3600mAh for Streamlight X Series Flashlights 2-Pack

18650 battery. Despite limited details specifically item length I took the plunge. And I couldn't be happier. It matches the battery that came with my headlamp (Nebo Einstein 750). So many different batteries available that all claims to be 18650 left bewildered. This battery measures approx 2,3/4 inch. They're also a higher milliamp. So, maybe they'll hold a longer charge? Or just be brighter? They have built in usb c for easy charging without a separate device. I haven't fully tested the battery yet for durability or runtime. Even if the battery was a quarter inch longer I'm thinking it might still fit, because of the coil/spring that secures the battery's terminals. Now having 3 batteries to rotate with I'm hoping to not have to replace them anytime soon.

They were very bright and they work very well

Larger diameter than standard 18650 batteries

Great product! A+

These seem to be good batteries, and I like the USB-C charging design which even includes and LED to let you know it is charging or done charging. However, in my flashlight the length appears to cause some issues It will power the flashlight, but only when the battery cap is slightly untwisted -- but not too untwisted. In regular use this would be very challenging as it also flips between settings improperly with this battery installed. However, the batteries themselves are probably fine, I just can't use them. Wouldn't recommend if you are purchasing for your Streamlight HL-X. EDIT: I was able to get them working better, just requires twisting very tightly!

Got these for my Nebo 1500 lumen head lamp and they did not disappoint now i have a battery charged and ready to go when one drains in a 10 hour shift i think i had my light on a good 7-8 hours, i used both batteries the second one didn’t drain all the way so i am very happy with these batteries now i hope they last

excellent life

These are Chinese 18650 lithium ion rechargeable batteries that have a USB micro B port with an indicator light that lights up green when fully charged (red when low). Took about 5 to 6 hours to fully charge. These will not fit into a flash light that uses CR123 batteries because they are a little thicker than the CR123. They fit perfectly in my Pelican 7000 and Wowtac A1S. The Pelican 7000 uses two CR123 batteries inside of a plastic sleeve that makes it the same length and width as an 18650. Comes with two batteries and one plastic case. No charging cable included, which kind of sucks. Means you have to buy one if you don't already have one. Otherwise, not a bad deal.