Book Style Power Bank with large capacity of 20,000 mAh enough to charge your Smartphone 300% and your Tablet 200% and still have some left. This new technology using the same batteries found in Smartphone that fits ins slim style case. The Li-Polymer battery packs a lot of power in thin footprint. It has Dual USB Port that can simultaneously charge 2 devices and it has power indicator telling you what is left in the power bank. It has a on and off button to stop charging and also has LED light that can shine for a long time. All metal body that will absorb the shock and has intelligent chip that stops charging the device when it see the device is fully charged thus conserving power in your power bank for later use. Comes with Micro cable for charging the powerbank.Details:-20,000 mAh power capacity in power bank-2 USB port 1 amp and 2.1 amps -Super Slim book style under 9mm thick.-Auto power and charging monitor built in.-Micro cable included.-Fully compatible with all Apple devices, Samsung Devices, HTC, Nokia 1 year warranty on this product for any defect.