This modification is highly recommended for those who can't play on a mouthpiece with a gentle rim bite like the original Bergeron model. The rim bite has been modified with a cut, and then silver plating has been reapplied. It's a sleeve type, and the mouthpiece side has also been replated. A standard #5 sleeve is included. The sound, personally, is almost the same as a regular Bergeron Studio. I thought the sound might be slightly larger in volume due to the cut, but perhaps the sound didn't change much because the lips naturally fit inside.