The Astoria 20000mAh 22.5W Power Bank has two USB-A output ports and two input ports (a USB-C and a Micro-USB port). Each output port has a maximum output of 18 W when used alone. The combined output of the two ports can reach 5V/4.5A, so it can be used to charge both phones and tablets. The high-precision resistance, inductance, and capacitance components and advanced circuit chips can easily tackle overcharging, over-discharging, overheating, short circuits and other faults, offering reliable protection for both the power bank and devices. The high-density lithium-ion polymer battery provides lasting and reliable battery life for devices such as phones, tablets and digital cameras. So you can recharge wherever you are — in the office or on the go.