Buffet Crampon Antoine Courtois Tenor Bass Trombone AC424 Florida Accessories ICON 5J Large Bore Silver Plated ① The size is equivalent to 5G, and the rim is thin, so it feels light when playing, but it resonates well. ※ Another of the same model is also listed, but this one, ①, has a slightly more compact impression, which is a difference between individual instruments. I think you can use it regardless of whether it's a European or American type. I used it for a while (2-3 months), so there are scratches on the shank from normal use, but there are no dents or plating剥がれ (peeling). (There is some plating corrosion? dirt?) I would like to sell it to someone who understands the above.