I received mine today (in the UK), the jump leads each have an inline "box" which I presume contain some sort of protection circuitry (this isn't shown in any of the demo videos I had watched, although not really an issue).
The instructions that came with the device mentioned something about the lights on the front reading like a charge level for the car battery, and the device shouldn't be used if less that three lights show - Again I presume that this is to protect the device.
The sticker on the back says the device is rated for 150A starting current with a 300A peak current, and the device should be used with engines smaller than 2.5L "for best performance".
The good news is it charges my phone pretty quickly and shuts off automatically after a few minutes of the phone being fully charged
, although interestingly there is a small "explosive" sign on the back of the device
I'd quite like to try this thing out properly
, but for now it shall sit in my glove box and probably not see much use! If anyone is interested in pictures of the device or the instructions that came with it I'd be more than happy to post a few.