Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Does what it's supposed to do

It was shipped well before the estimated date which was nice. Apart from that, it works fine. Plug into your charger and voila! Although two improvements could be made: Retractable cable, on/off button on the plug (my car does not shutdown power on the charger when it is turned off).One important thing is this thing does not check the current going through the charger. I plugged this device before turning the ignition on, it starts to charge the device, but during the period where car drains power from the battery to start, the current decreases which might damage your device. Just be aware. Otherwise good product.