This is a Dieter Otto 180k-JN in a raw finish. This horn is about four years old, and was used in the Metropolitan Opera orchestra. It is a .472" bore, and has a silver plated inner flair. Compression is still fantastic, and slides move freely. This instrument has a Jeff Nelson nickle leadpipe, and 12.2" flair. The construction of this horn is fantastic. Would be an ideal chamber, or orchestral instrument. It even comes with a Marcus Bonna Case! .Serial number is 4514.