Selmer 53 Series III Soprano Saxophone Enhanced Resonance Reducing the size and weight of the ribs (the body plates supporting the posts) by 30% results in a more free vibration of the instrument and enhanced resonance.Mark VI Neck Angle The angle of the neck, copying that of the fabled MARK VI, redirects the airflow and mouthpiece position to enhance response.Rivet-less Metal Tone Boosters Kik pads provide an airtight seal. Rivet-less metal tone boosters result in projection without buzz or distortion.