The 108G is very similar to the Bach 1.25G and 1.5G, with a nearly identical cup, when you allow for the Wedge oval shape. The Bach 1.25G and 1.5G have very similar cups, with the main difference in the two mouthpieces being the softer bite radius of the 1.25 rim, which makes it feel bigger.
- ID: 1.08 inches, measured at .05 inches into the cup.
- Throat: .280 inches
- Note: Some bass trombones, for example some vintage King models, have an extra deep receiver. If your mouthpiece inserts more than 1.25 inches (31 mm) into your leadpipe be sure to select the BT Deep Receiver option when ordering bass trombone mouthpieces.