I use this in my Olight Warrior X Pro as a backup cell. The X Pro is an amazing light, but if you need extended run times in the field it’s great to be able to swap in a charged battery and not have to worry about needing to charge the only 21700 battery that fits.

Expensive as batteries keep creeping higher in price, but worth it if you might need extended run times and don’t have a charger available.

I bought this battery so I could have a spare to my Olight Seeker 2 Pro. Like the battery that came with the light, it arrived at about 3.58V and took over four hours to fully charge to 4.20V. As with other Olight customized batteries, (rechargeables dedicated to a certain model flashlight) it has to be charged while in the flashlight with the magnetic charging system. It would be nice to be able to charge it outside of the flashlight in an external charger, such as the Nitecore SC4, but it can't be. It wouldn't fit anyway because of the plastic rim around the positive terminal. The battery measures 75.5 mm long. The battery performs as expected and I am happy with the purchase.