This is a custom product compatible with piston tubas from recent B&S and Meinl Weston models. By minimizing the internal protrusions found in standard pistons, the airflow is smoothed, resulting in significant improvements in both high and low registers. The response and playability are enhanced, making for a very comfortable playing experience. The list price has increased (around 250,000 yen), making this a very good value. There are some scratches from use, but they do not affect performance.