When designing the AC 4, the aim was to subtly integrate the functions required to provide the best level of comfort. The reason for this is that until now, office chairs were either designed with a view to aesthetics or to functional characteristics. The AC 4, by contrast, integrates its ergonomic properties in such a subtle way that the constructional tricks are hidden away. The AC 4 creates a balance between advanced ergonomic functionality and subtle design. The innovative technology is neither showy nor hidden under foam padding. This makes the AC 4 an iconic object with an aura of elegance coupled with uncompromising functionality.