2 piece set-USB charger with overcharge protection function, input: DC5V, output: DC4.2V-420mA Safe: The red indicator light indicates that the device is charging, and the green indicator light indicates that the device is fully charged.LED when fully Charged,Smart and Portable USB Chargers with Charge Protection Compatible with Wireless Soldering irons. Charging steps: Remove the tip of the soldering iron, rotate the charger into the soldering iron device, and finally plug it into the USB port to obtain power Advantage: Compatible with more soldering iron devices, not affected by the different shapes charger port types provided by the manufacturer.Plug and play, light-weight, portable, and light-weight small device. Let you carry it anytime, anywhere. It is small in size and can fit in pockets and other items Wide Campatibility: The USB charger cable is suitable for most USB charging devices. Please confirm whether the connection port matches the device before use