Apple Nike + Ipod Sports Kit MA365LL/F 

Niike + iPod Sport Kit transforms your iPod nano into a personal workout coach. 

This wireless sensor and receiver combination works exclusively with your Nike+ shoes and

iPod nano to give you real-time feedback during workouts and let you track your

performance on your Mac or PC

    Compatible with iPhone 3GS, iPhone 4, iPod Touch (2nd, 3rd, and 4th generation),
        and all iPod nano models

    Hear how you run - The Sensor and Receiver enable your Nike+ Shoe to
        talk to your iPod with every step