Reliable, safety-tested and certified portable power where and when you need it. Reserve Power Banks deliver safe, dependable power for phones, tablets, GPS units, wearable and most other devices that charge via USB. Charge On The Go - UL-tested and certified Li-Ion batteries recharge from any wall charger, car charger or laptop/PC. Then connect your Lightning cable " or the micro-USB cable that ships with each Reserve Power Bank " to recharge your devices. LED power gauge shows the battery's charge capacity with the push of a button. Slides easily into any pocket, purse, back or backpack so you're never without power. Charge two devices at the same time - Reserve Power Bank's max-rate charging port delivers 12 watts of charging power (5 volts at 2.4 amps), and a second charge port delivers 5 watts of power (5 volts at 1 amp)perfect for smartphones and wearables. How far will 18,200 mAh take you? Smartphone - Up to 7.3 charges Smartwatch - Up to 55 charges Large Tablet - Up to 2.5 extra charges. Built & Tested for Long, Reliable Life Reserve Power Banks' safety-certified Li-Ion cells are secured inside a drop-tested, durable polycarbonate shell. Built-in power management circuits prevent the battery from overcharging, and from charging the attached device at a rate faster than it can safely handle.