EFEST SLIM K4 Quad USB-C Battery Charger is the latest charger introduced in the K series. It is manufactured by the world famous EFEST. Be it the innovative auto smart cut off technology to the USB-C charging capability - the EFEST SLIM K4 Quad USB-C Battery Charger delivers powerful features. The SLIM K4 can charge at both 1A per channel with 2 batteries and 0.5A using 4 channels. The presence of smart indicator light informs the vaper when the cell is in charging status. The indicator will turn into a solid white colour when the battery is fully-charged.