This bundle includes two items: 1) an ultra slim, lightweight and comfortable sport armband that holds a 3G iPod nano with a connected Nike + iPod Sport Kit Receiver AND 2) a Sensor Case that holds the Nike + iPod Sport Kit Sensor. Features of the armband include a cord management flap to store and manage the earphone cord, a clear protective window cover with full navigational control, and reflective materials for nighttime visibility. The armband is washable and adjusts to fit arms 8" to 16". For larger arm sizes, an Armband Extender is available. See model EX3 which increases the maximum arm size by about 6.5 inches. Tune Belt"s Sensor Case allows you to use the Nike + iPod system with nearly any shoe. It quickly and easily attaches around shoe laces to securely hold the Nike + iPod Sport Kit Sensor. The Sensor case works with 2nd, 3rd and 4th generation nano. The armband only fits third generation nano. (This bundle does not include the Nike + iPod Sport Kit which is sold separately.)