The Vandoren Masters ligature, which has been discontinued. It was a popular ligature known for its natural feel when playing, but unfortunately, it has disappeared. Now, it lives on in the M/O ligature, but I think there's a significant difference between the single-screw and double-screw versions. It's lighter than the Optimum ligature and provides a more solid feel than the M/O ligature. Because it has two screws, you can adjust the tightness to achieve your preferred playing feel. The black and nickel-plated versions are for clarinet. The gold-plated version is for alto saxophone (Selmer size), but it could also be used on clarinet. Thank you!