The Efest Slim K2 is charged with a USB cable and is built with a high-quality fire retardant material. The lightweight, portable design is convenient, stylish, and eye-catching.

The long-lasting spring is made of piano wire, which provides a smooth gliding action when installing and removing batteries. Steel cathode with low resistance and hard chromium plating processing to achieve a more accurate charging voltage.

Fast charging mode: 1.0A (4.2V -- 2 cells * 1.0A) | Activation function
Reverse polarity protection | Auto-detect charging function
Over-charging protection | Short circuit protection

Compatible with Lithium IMR 3.6V/3.7V Batteries:
10440 | 14500 | 16340 | 17340
18650 | 18490 | 18500 | 18650
26500 | 26650 | 20700 | 21700