Nike+ SportBand (Black/Volt) Includes waterproof, durable Nike+ sensor that fits inside your shoe, transmits run data wirelessly to SportBand Removable Nike+ link connects to your computer via USB for transfering run data and automatic charging Join challenges and connect with friends as a member of Nikeplus.com--view/share routes, find popular running areas, share activity on Facebook or Twitter Requires Nike+ ready shoes; Mac OS X 10.3.9 or later, or Windows Vista, XP (SP2), Home, or Professional; Internet access to connect to Nikeplus.com