The AK400 audio player is characterised by an asymmetrically designed body with a back showing a refined pattern. When light hits the device, it is diversely reflected like sound waves, which are emitted differently, depending on the environment. The stainless-steel volume control dial integrated into the side has a knurled surface with good tactile qualities, enabling precise settings. By pushing and turning this dial, several functions can be immediately selected so that the thumb suffices to operate the player.