Witten (Germany)  Troy (USA)  Development center  description acoustics material/product development material testing prototype workshop CAD design process/production line development production line construction design center recycling process development    Development center description acoustics material/product development prototype workshop CAD design process/production line development    Rugby (Great Britain)  Incheon (South Korea)  Development center  description acoustics material/product development    Development center  description acoustics material/product development CAD design