This is a gold Volare BT-01R. It's a model for F tuba, and I believe it's a higher-end equivalent to Yamaha's Bobo Solo. It seems that gold models haven't been widely available in recent years. The shank shows signs of use, but overall it's in relatively clean condition. I'm selling it because I no longer use it. When I played it, it was very easy to blow from top to bottom, and above all, it was impressive how the intonation didn't tend to go sharp. Quoted from the following site: Rim Inner Diameter: 32.03mm Rim Width: 8.35mm Cup: Shallow Throat Diameter: 7.50mm The BT-01R is a type that has the same specifications as the Volare's representative model, the BT-01F, but with a rounded rim. It was a big surprise that the sounds of each had different characteristics, even though they were supposed to have the same specifications. The BT-01F was characterized by a brilliant and powerful sound, but this mouthpiece is characterized by a very gentle and sweet sound reminiscent of the European countryside, and it also produces a good volume.