OREI Ultra Slim External Battery is a portable power bank with an integrated 3500mAh Lithium-Polymer rechargeable battery with 1.0 Amp of output ready to charge up your smartphones and tablets. Its roughly the size of an iPhone 5, the UNICHARGE-EX has an elegant yet modern brushed aluminum surface and with a thickness of only 0.375", you can bring it just about everywhere you go. Keeping your important mobile devices charged while enjoying the envious looks from bystanders! ARCTIC Power Bank 4000 is not just for your smartphones and tablets; it can charge just about any USB-powered devices, including Bluetooth headsets and wireless speakers as well! Smart charge level indicator keeps you informed how much charge power is left so you can always keep your mobile devices charged when needed. It is equipped with a charge controller that extends the battery life and a protection IC which protects your mobile devices from short-circuit, over-voltage/current. OREI UNICHARGE-EX includes with a 2-year limited warranty.