Characteristics: 1. Compatible with four cylindrical lithium batteries (3.6V / 3.7V). 2. It can charge two 32650 large-size batteries or four 22650 large batteries at the same time. 3. Automatically adapt to USB input power, quickly and stably recharge the battery. 4. The input USB charging cable is integrated with the charger, easy to carry and charge. 5. Reverse polarity, over-voltage, over-current, over-charging protection. 6. Activating 0-volt over-discharged batteries. Specifications: 1. input?DC5.0V 2.1A 2. output: 4.2V±0.05v 1A *2(CH1/CH4)/ 4.2V±0.05v 0.5A *4 Four dual-color LED lights corresponding slot display? a. Charging: Red light b. Full power: green light c. Fault: Red flash