Armband for iPod nano 4th generation when used with a connected Nike Sport Kit Receiver AND Sensor Case to hold Nike + iPod Sport Kit Sensor (does not include sensor) Ultra slim and lightweight neoprene armband fully covers 4th gen iPod nano and Nike + iPod Sport Kit Receiver (not for 5G nano) Sensor case securely attaches to shoe laces to hold Nike + iPod Sport Kit Sensor Armband has hidden pocket to hold key or money; Securely stores and manages earphone cord Armband has clear, protective window cover with full navigational control Comfortable and flexible armband adjusts to fit arms 8" to 16" and an Armband Extender is available for larger arm sizes (see EX3); Reflective material for nighttime safety.