This is an Apple Ultra Thin Aluminum USB Keyboard with Numeric Keypad A1243 MB110LLA.
The Apple Keyboard with Numeric Keypad features an elegant, ultrathin anodized aluminum enclosure with low-profile keys that provide a crisp, responsive feel. It also has function keys for one-touch access to a variety of Mac features such as screen brightness, volume, eject, play/pause, fast-forward and rewind, Exposé, and Dashboard. Its extended layout includes document navigation controls — page up, page down, home, and end — and full-size arrow keys for playing games and scrolling through documents. Its numeric keypad is perfect for spreadsheets and finance applications. And two USB 2.0 ports enable you to connect your mouse as well as a high-speed peripheral such as a digital camera or printer.
Requires Mac with built-in USB port and Mac OS X v10.2.x or later.