The bands are fully replaceable, and if you don't want to wear the S Band on your wrist, a clip accessory can attach it to you or your stuff elsewhere on your body.
The S Band will use BT Smart (aka Bluetooth Low Energy) to communicate with the phone it's paired to. It is not clear what will be its battery life. Surprisingly, the device does not have the heart rate monitor its Gear-branded cousins are equipped with.