Ansmann lithium batteries in size 21700 with a voltage of 3.6 V and a capacity of 5000 mAh, ideally suited for use in modern LED flashlights, headlamps, laser pointers, etc. Particularly safe thanks to the integrated protection circuitry, which guards against overcharging, overload, short circuits, and deep discharge. There is a charge status LED at the positive terminal of the battery. During charging, it lights up red, and when the battery is fully charged, it switches to green.