Trombone KING 3B Concert Bore size: 12.9 mm. Bell size: 8 inches. The bell engraving appears to be hand-engraved. This is an old KING from the good old days. It's from a time when they were really well-made. Although it's quite old, I think it's in very good condition for a used item. There are three small dents, but they do not affect the playing (please check photos 6, 7, and 8). There is no peeling of the silver plating on the hand-held parts or the neck area, which are prone to peeling. Originally used by a professional. The slide moves normally, but there is a slight rattling sound in the distant positions. The inner slide tubes are clean with no peeling. The sound is amazing! As expected from KING during its best period! It's light yet has a certain weight, and I think it will perform at its best in big bands and jazz combos (this is my personal opinion). Mouthpiece not included. Case is Yamaha. Will be shipped wrapped in bubble wrap. Thank you.