Nike + iPod Sport Kit - USA (OLD VERSION)[Retail Packaging] Compatibility: iPod nano 1G, 2G, 3G, 4G, 5G, 6G; iPod touch 2G, 3G, 4G; iPhone 3GS, iPhone 4 Waterproof, durable Nike+ sensor slips into pocket under sockliner of the left Nike+ ready shoe iPod tracks your progress, providing feedback on distance, time, pace, and calories burned Nikeplus.com lets you evaluate your performance history, set goals, and challenge other runners to a virtual race iPod touch, iPhone 3GS, and iPhone 4 do not require receiver--sensor is available separately