Typical of AmazonBasics goods also this external battery comes in a neutral cardboard box included a microfiber bag and a micro USB cable for charging your own batteries.
Although the external battery does not measure exactly the height, width and depth of a credit card, but is also not too far from it. Precisely for this reason there is no need for a USB port, which makes the loading of all devices that are not charged via microUSB, impossible. One can therefore apply this battery only for devices - which are loaded by the hidden plug - which are themselves also loaded via microUSB.
The battery has a capacity of 2,000 mAh, which means that most smartphones with full charge this battery can be fully charged once before the battery needs to power itself. I think it should be loose enough for emergencies, because after all, external batteries for such purposes intended and should not be used as a standard charging method.
Although I speak all the time of smart phones, but of course you can order also connect your other micro USB devices and recharge.