The battery measures in at just slightly thicker than the iPhone 5, but its contoured housing and similary-sized dimensions means it can slip in your pocket as easily as your phone. And while the Jackery Air's 5600mAh isn't the largest you can buy, it's certainly capacious enough given the back battery's slim form factor.
Charging it from dead takes about six hours, but it promises to then boost the battery life of your iPhone or smartphone up to 200 percent and it can be used with larger devices like iPads and other tablets. It's on sale now for $80 for a limited time, making it a pretty reasonable way to never have to deal with a low battery warning ever again. More here.