PowerTones used to come in sizes. I used one in an alto Meyer for a while. Since they come in packs of 3, I stuck one in my Bass Clar MP and liked the results. They are a good product. Unlike putty, they keep their shape when touched during mouthpiece cleaning. Putty and wax is more flexible which is a pro/con. Putty or wax only costs $2 for enough to do several mouthpieces.