Review on 2-Pack SNSYIY 3.7V 3600MAh USB Rechargeable Button Top Batteries For Klarus Flashlight (XT11X, XT11GT, XT30R.) by Eddie Duncan

These are 3.7V 3600mAh rechargeable lithium batteries that can be charged with micro-USB cable.It came in 2 packs inside a plastic storage case that fits both perfectly and while it didn't come with micro-USB cable, people have plenty of micro-USB cables laying around these days so it's not a problem at all.It's cool that it has micro-USB port on top of the battery so you can simply plugin the cable and recharge these batteries using any standard USB powered port. I have few flashlights that use this size and capacity battery so this will serve as spare batteries to replace while old one is being charged. It's the same capacity in mAh and exact same size so no issue with compatibility. These batteries have many built-in protection and can be recharged over 1500 cycles so should last me lifetime. A great spare batteries to have around for emergency, especially when in outdoor like camping. I appreciate that there's a small LED light that shows in red and green color to indicate whether or not charging is completed.