Marcinkiewicz standard trumpet mouthpieces are arranged in a logical ascending
order from deep to shallow and wide to narrow (0 to 15). This arrangement permits
players to select mouthpieces by precise increments of depth to find the correct
cup volume required by their situation.
For example, if a No.7 trumpet mouthpiece
is too deep and a No.10 too shallow, a No.8 or No.9 may be the best logical choice.
Note that No.6 - No.10 are similar to a Bach 10-1/2C.