Perantucci - Tuba Mouthpiece PT-42, Cup: 33 mm diameter / Deep, pure funnel shape, moderately round at bottom., Rim: 7.5 mm / Rounded inner and outer edges.Bore: 8.3 mm. Model PT-42 provides a strong fundamental with a clear and colorful sound. It has great strength and excellent projection. All the virtues of the funnel-cup philosophy incorporated into a large mouthpiece, recommended for large contrabass tubas, gold plated