When desired by Nicanor Zabaleta the Horngacher concert harp-makers developed the unique damping mechanism. Because of constant technical development the function now is optimized. The technical splended  mechanism with an eighth pedal damps the wire strings. By using the pedal a brass plate covered with felt moves from the tuning mechanism to the strings. The eighth pedal is located on the left side, close to the B flat-pedal. The space between is the same as between all the other pedals.