Our Mouthpiece Inserts allow the artist to change the instrument’s tone, focus, breathiness, pressure, definition, and volume. These change the volume air flow and turbulence inside the air chamber increasing or decreasing laminar airflow from the artist's breath. The extensions are stackable and the cap or cone to be added at the end. *Cap (3mm): Contoured mouthpiece interface, improves seal, matches a natural mouth shape. Subtle shift in tone, focus, breathiness, pressure, definition. Extension (25mm): Increased pure tone, compact focus, breathiness, free-blowing pressure with smoother definition. Cone: Internal mouth interface. Greater increase in color brightness and volume, and an increase in pure tone, breathiness, free-blowing pressure, dynamic range, and flexibility, with a slightly diffused focus. View Mouthpiece Characteristics Chart Here Terms and Conditions: Shipping, Returns, Cancellation, Warranty * = Included with a RolBec Flute purchase