BJ-468: the lightest model from the BJ trumpets the smalles bore size, but still large
BJ-1: heavier than BJ-468 larger bore size than BJ-468 same bell shape as BJ-468 but with soldered rim same leadpipe as BJ-468 heavier tuning slide then BJ-468
BJ-2: exactly the same model as BJ-1 but with larger bore size
The BJ-2 has a very large and dark sound. It's a great trumpet for Jazz. The BJ-468 is a more versatile trumpet, also for Jazz, Big Band also Classical music.