Like the instrument, Laskey Tuba Mouthpieces are a towering presence in low brass playing. With a thicker sound and more complex geometry, every aspect of a Laskey Tuba Mouthpiece, from the iconic rim to the exterior shape and cup, has been carefully designed to provide the clear articulation, precise slotting, and crisp response. The B Series Tuba Mouthpiece is a deeper version of the G Series, providing a wonderful, full sound in the low register. A great choice for those trying to make smaller tubas sound bigger. After testing numerous tuba makes and models, two shank sizes were developed to meet the needs of a wide variety of mouthpiece receivers: American (US) shanks fit most American made and styled instruments, while European (EU) shanks fit many European made and styled instruments, with the exception being most 6/4 CC tubas, which require the EU shank. American (US) Tuba Shank Measurements: Top: 15.44mm/0.608"Bottom: 13.31mm/0.524"Taper Angle: 1.41 degrees European (EU) Tuba Shank Measurements: Top: 15.85mm/0.624"Bottom: 13.77mm/0.542"Taper Angle: 1.37 degrees Note: Unless in stock, Gold Mouthpieces are made to order and are FINAL SALE with no trial period or returns. Please expect 3-4 months for delivery. For more information please contact us. Comparison Chart Measurements Metric Imperial