The universal Rose Stone is small enough to easily fit in a purse, briefcase, backpack...even in the palm of your hand. This lightweight but powerful battery is perfect for work, vacation, and every day on-the-go. This extended battery contains a rechargeable 5200mAh lithium ion battery strong enough to charge two smartphones simultaneously. When life takes you away from an electrical outlet, Powerocks are just the thing to keep you connected by charging smart phones, tablets or other USB-chargeable devices. Conveniently small and surprisingly powerful, these handy batteries easily go wherever you do.