The wireless headphone system RS 140 is a closed system with excellent audibility, balance and auto-tuning. Headphone and transmitter with integrated load handle form a compact unit, which solves charging and storing the headphone in an elegant way. The characteristic of the headphone is the angled earpiece and the very complex shape of headband and fork. The angled rotation axis and the elliptical shape of the earpieces as well as the asymmetric mounting of the forks consider the anatomy of the human ear and ensure an optimal adjustment to the individual wearing situation – and prevent the appearance of standing waves and thus a distortion of the sound. The entire design and also the ergonomic adjustment based on several 3D-models of the human head was completely generated in a CAD environment.