Perantucci Tuba Mouthpiece PT-88+ Heavy Wall Model Silver Plated
 
These mouthpieces are all new old stock and also include the "Mr Tuba" stamped on the mouthpiece from the factory.
 
Perantussi say the following about this mouthpiece.
The ultimate mouthpieces for musicians who desire and thrive on maximum dynamic range, immense tonal breadth and a powerful and commanding low register. The PT-88 is ideal for those who perform in large symphonic ensembles. Resistance is adjusted for good control and efficiency.

This mouthpiece makes full-range capabilities possible for a vast number of musicians. The recommendation for strong and powerful players
 
Cup Diameter: 33.50 mm, wide, deep rounded
Rim:  7.00 mm, flat, well-defined inner edge
Throat bore:  8.10 mm 
Resistance: Open-blowing
Standard Large Shank for most European Models (recommended for most instruments)
 
Please note - For mouthpieces purchased online I am not able to offer trials - if you are looking to try this mouthpiece, please contact Mr Tuba at sales@mrtuba.com
 
I find mouthpieces impossible to take photographs of due to the reflections, so the image shown in the stock image from Perantucci.  I am happy to supply additional images if you send me a message.