The Efest Slim K4 USB-C Charger is an intelligent, four-bay, lithium battery charger with a Type-C USB charging port. The SLIM K4 Charger can charge four batteries at once and is designed with some smart functions, such as: auto-detect charging monitors and charges each slot independently low voltage smart activation recovery 0V activation recovery. It is compatible with Lithium IMR 3.6V/3.7V batteries: 10440, 14500, 16340, 17340, 18350, 18490, 18500, 18650, 26500, 26650, 20700, 21700. The LED indicator will show you the status of charger. The indicator light will turn blue in standby mode/full charged white while charging. Please note: a 2A USB port is recommended. Batteries are NOT included. Batteries available here See our battery safety page for information on safety SPECIFICATIONS: Four-bay charger can charge up to four batteries simultaneously Compatible with many battery sizes, including 18650, 20700, 21700 & 26650 Charging speed: 4 x 0.5A, 3 x 0.5A, 2 x 1A, 1 x 1A Automatically stops charging Reverse polarity protection Input: Type-C USB DC 5V 2A Output: DC 4.20V±0.05V 0.5A*4/0.5A*3/1A*2/1A*1 PACKAGE INCLUDES: 1 x Efest Slim K4 USB-C Battery Charger 1 x Type-C USB cable Warranty card