Efest K2 charger is a dual battery charger, LED indicator USB charger, safe charging mode, automatic overcharging protection, reverse polarity protection function, low voltage smart activation recovery function.

Specifcation : Ultra compatible with a variety of 3.6v/3.7v lithium batteries

10440, 18500, 14500, 18650, 16340, 26500, 17340, 26650, 18350, 20700, 18490, 21700.