Features: The first time you need to install the 18650 flat head battery,then press the button on the back of the circuit board to activate the use of this product. 5.5x2.1mm port output is DC 12V,Suitable for wifi Router LED Strip CCTV Camera and more 12V device. When using the powerbank, you can not charge the power bank,Suitable for equipment that does not require voltage regulation. There is no stable voltage, 3 batteries are connected in series, the maximum is 12.6V, the minimum is 8V, the voltage changes with the battery capacity Specifications: Item Type: 18650 Li-ion Battery Charger Box Material: ABS Color: Back,Blue Size: 93x75x25mm 5.5x2.1mm input: DC 12-13V 2A 5.5x2.1mm port output: DC 12V 3A max Package includes: 1 X DIY Power Bank Box(18650 batteries are not included) 1 X 5.5x2.1mm to 5.5x2.5mm cable