This Efest Slim K1 is a single-slot battery charger, so you're able to quickly charge two batteries simultaneously. It is very capable for it's small size, in that you're able to charge different battery types in each port of the charger. While charging a single battery, the Slim K1 provides a charging current of 1A and charges quickly, using a USB port for power.
Each slot on the charger contains an active LED battery level indicator to provide the status of each battery’s charge. The Slim K2 Charger is also equipped with features like Reverse-Polarity Protection, Short-Circuit Protection, and Overcharge Protection, to ensure the protection of your charger and the batteries.