The Nike+ SportBand tracks your distance, pace, time and calories burned while you run in an easy-to-read display. It's also your connection to the world's largest running club on nikeplus.com, where you can log and review runs, get training advice, challenge friends and more. The SportBand is easy to use. After each workout simply remove the Nike+ Link and connect it to your computer's USB port to go to nikeplus.com, where you can see your progress and take part in the Nike+ community. The Nike+ SportBand memory saves 30 hours' worth of your workouts for review. It features enhanced display quality, improved water resistance and is available in two new colors. Requires Mac or PC; Mac OS X v10.3.9 or later, Windows Vista, or Windows XP (SP2) Home or Professional; Internet access (Broadband recommended). Tracks distance, pace, time and calories burned. Memory captures and stores 30 hours' worth of running data. Removable Nike+ Link for quick connection to nikeplus.com. Doubles as a watch with time display. Enhanced display for increased readability and improved water resistance. Automatic battery recharge when Nike+ Link is plugged into your computer. Stainless steel popper closure to hold band in place and provide an adjustable fit. Durable polycarbonate case. Pre-curved polyurethane band for lightweight comfort. Includes Nike+ sensor to be placed in your Nike+ ready shoes. One size.