This is a Vandoren AL5 alto saxophone mouthpiece. I used to see AL3s often, but nowadays, mouthpieces with wider openings like C.D., S90-200, and C☆☆ seem to be preferred for alto sax. Compared to the AL3, this AL5 has a wider opening, and even with a thin reed like a 2 1/2, it produces a sound rich in flexibility and fullness. I used this with blue box 2.5 reeds and Légère 3.00 reeds in college. It's a mouthpiece that produces a soft sound while still allowing for powerful playing. I feel this is a good piece, even as an individual item.