There's a 6,000 mAh battery in that sky blue case, which Juno Power says is also good for a 12-volt boost at 300 amps. The company says it's robust enough "to jumpstart almost all four-cylinder and six-cylinder engines," but in case you're wondering how 300 amps can run safely through those tender cables in the image above, it's possible that Juno Power is playing casual with the meaning of "jumpstart;" elsewhere on the product page we're told that the Jumpr " is capable of jumping a completely dead car battery in minutes." So it sounds like this is less of a jump for your car and more of a series of quick, restorative hops of electricity - or, in other words, something we call "charging."
There are other devices that do the same thing (like this and this, two more expensive options) or you can get two specific tools for each job (like this and this, which together cost the same as the Jumpr). Not that it matters - you won't care to argue semantics or originality if the Jumpr can keep you from being stranded outside that Swedish death metal concert at 2:00 AM. It goes on sale on May 1 and costs $69.99.