Yamaha Tuba Mouthpiece Signature Series Standard Sergio Carolino. This is an all-around mouthpiece suitable for solo performances on F tuba or orchestral use on C tuba. - Inner rim diameter: 32.44mm - Throat diameter: 7.5mm - Silver-plated finish - Rim contour: Slightly flat - Rim thickness: Standard - Cup depth: Slightly shallow - Backbore: Standard Thank you for viewing. It has been used a few times, so there are marks on the mouthpiece shank, but otherwise, there are no noticeable scratches or stains.