This is the 3rd generation Nano.

The 3rd generation iPod nano’s slick click-wheel lets you navigate quickly to any of your videos, photos, music, e-books, calendar events, and contact database. The durable, touch-sensitive surface responds to your every whim, and gives you total control of the experience. No matter what you’re looking for, iPod makes it easy to get just what you want.

Because it uses flash memory, it’s unaffected by vibrations, so it’s a perfect choice for the gym, motorcycling, or other active pursuits! The slim nano is housed in rugged aluminum, and gives you up to 24 hours of music playback, or 5 hours of video with sound on a single charge. Big things really do come in small packages!