Perantucci mouthpiece shank size

[jamsav]

Does Perantucci not differentiate shank size?

[tubalux]

"Perantucci tuba mouthpieces are available with the following shanks:

No Indication: (15.2 mm)Standard shank, for contemporary CC and BBb tubas with large receivers.
"S" on shank: (14.8 mm)One size smaller, for CC and BBb tubas with small receivers and most Eb and F tubas.
"XS" on shank: (14.5 mm)For Eb or F tubas with particularly small receivers.
"AM" on shank: (14.2 mm)For instruments with extremely small receivers."

That's what's on the tubamania website.

[jamsav]

"Perantucci tuba mouthpieces are available with the following shanks:

No Indication: (15.2 mm)Standard shank, for contemporary CC and BBb tubas with large receivers.
"S" on shank: (14.8 mm)One size smaller, for CC and BBb tubas with small receivers and most Eb and F tubas.
"XS" on shank: (14.5 mm)For Eb or F tubas with particularly small receivers.
"AM" on shank: (14.2 mm)For instruments with extremely small receivers."

That's what's on the tubamania website.

Trying to order one from Custom, no sizing options offered
I will call them tomorrow-

[jamsav]

"Perantucci tuba mouthpieces are available with the following shanks:

No Indication: (15.2 mm)Standard shank, for contemporary CC and BBb tubas with large receivers.
"S" on shank: (14.8 mm)One size smaller, for CC and BBb tubas with small receivers and most Eb and F tubas.
"XS" on shank: (14.5 mm)For Eb or F tubas with particularly small receivers.
"AM" on shank: (14.2 mm)For instruments with extremely small receivers."

That's what's on the tubamania website.

Trying to order one from Custom, no sizing options offered
I will call them tomorrow-