It’s a horrible feeling, helplessly watching your laptop’s battery bar inch to zero on a flight. This sleek device is designed to sit underneath your 13-inch laptop and double its battery life—packing an enormous 20,000 mAh of extra juice. But it’s not just a big ol’ battery. The Linedock provides your laptop with nine extra ports, ranging from high quality display outputs to USBs. Also, with a bit of extra cash the Linedock can extend the hard drive space of a device by up to 1 terabyte.