Travel with confidence without ever having to worry about your smart phone or tablet running out of power with this two disk stackable power bank from Sungale. Each disk of this uniquely designed battery charger has a 3000 mAh charging capacity. When stacked together, the two disks combine to double the charging capacity to 6000 mAh. Disks can each work independently to each charge separate devices or stacked together to increase the charging capability of a larger device. Take both disks with you wherever you go or if you don't think you'll be needing that much power, you can leave one at home, and take the other with you. These disks are small enough to tuck inside a pocket or stow away in a purse, briefcase, or backpack without taking up much space at all. If you want to increase the overall charging capacity even further than 6000 mAh, additional disks can also be added (sold separately) and stacked on top of the 2 disks. Each 2 disk power bank set includes a charging cable, a 30 pin, lightning, and Micro USB connecter to charge a variety of mobile devices.