biggest portable hard drive

What is the Largest Portable Hard Drive without power supply? I am looking for
the largest size I can find of portable HD that does not have a power supply. In this digitized day and age, external hard drives have become a staple in most
electronic repertoires. I am having difficulty in choosing a portable hard drive. Big Storage: 5 Great 1TB and Larger Hard Drives . What's the biggest portable external hard disk I can buy today? It has to . See more detail at http://biggest.portable.hard.drive.cheapharddrivesales.com