DEG Comparison Chart:

6.5AL - Medium cup depth, 25.40 Approx. cup diameter, Medium Wide rim shape, Small Shank
Compare to Bach 6.5AL Trombone Mouthpiece.

12C - Medium Shallow cup depth, 24.50 Approx. cup diameter, Medium Wide rim shape, Small Shank
Compare to Bach 12C Trombone Mouthpiece.