This is an aluminum cup mute for all tenor trombones, made in the USA of brushed aluminum by Joral. It has an adjustable cup so you can tailor the gap to your desires. The movement of the cup is rather stiff, which allows easy insertion without having to re-adjust the cup each time. Compared to the venerable Denisk Wick cup mute, the Joral is heavier, probably more dent resistant, and has a larger resonating chamber. It gives good feedback to the player, and a nice metallic buzz in the sound when pushed. This can be a very good mute not only for dance bands, but for concert bands and orchestras where more projection is required.
Joral actually makes two sizes of cup mutes for tenor trombones. This is the larger of the two. We do not stock the smaller model as we cannot find a horn that the small mute fits well. If you have something very tiny and vintage in your arsenal, maybe a Conn 2H, 4H or Bach 6, the small mute _may_ be what you need. All other trombones should use this larger cup.