As the official website of JK indicates, this JK USA line seems an elaborate copy of the V. Bach model in Mt. Vernon period. There is just one con; although I use this with my V. Bach Stradivarius, its shank size does not completely fit into the receiver of my instrument. So, I need to jam it in the receiver harder than usual (then the problem is completely solved). However, the quality of this mouthpiece is very good. Personally, I think this is much better than the current V. Bach.