Second Hand Patrick CR91S Commercial Trumpet Mouthpiece (one-piece) in very good condition.

Website Patrick:
There would be no Bach inner diameter comparison to this mouthpiece that I know of, but if Bach made one, it would be around a Bach 14 inner diameter. This mouthpiece has a shallow V cup design. This mouthpiece has more resistance than the old Jet-tones providing more endurance, better projection and an easier high end. The sound is full and resonant from the very bottom of the range to the top. The back-bore is matched perfectly to the top to give you a balanced mouthpiece.
CR (Comfort Rim) This rim profile falls between the classical models and commercial models and can be found on both series. This is the most narrow rim profile offered on the commercial models yet still remains extremely supportive. The high point is toward the inside of the rim, making these models “feel” slightly smaller.
91S:

• 0.6309 inner diameter measured at 0.30″
• 0.1410 throat
• 28 drill
• 1.0964 outside diameter