Features: The power bank is made of high quality material, very durable. 4000mAh large capacity: premium Li-ion battery cells add an extra 4000mAh to the battery life of your smartphone, tablet or digitalcamera. 2-ports: DC5V/1A + DC5V/2.1A, convenient to use. Slight shake to display the power. Dual-output, charge two mobile devices simultaneously. Simple design: connection ports are located on one end of the power bank. With battery power display, convenient to use.