The Nike+ Fuelband activity tracker, launched 2012, is encapsulated within a thermoplastic elastomer (TPE) skin. A flexible circuit board is mounted onto an injection moulded polypropylene (PP) chassis. The whole assembly (circuit board, processor, sensors, antenna, USB connector and LED lights), but excluding the batteries, is placed into a mould and injection over-moulded with a TPE skin in a two-stage process (inside then outside).