These are two tuba mouthpieces made by Yamaha in Japan for Roger Bobo, one of the foremost tuba soloists of a generation. The Symphonic is primarily for CC and BBb tubas while the Solo is for F tubas. Both are finished in silver plate.
The Solo mouthpiece features a clear focused tone that sings and projects, and is especially suitable for solo performances and for use with F and Eb tubas. Shown in first photo.
The Symphonic model is characterized by a warm tone, big enough to fill the concert hall with rich colorful sound. This mouthpiece is fairly bowl shaped and deep, and gives a fast and accurate response for 4/4 tubas. It may not feel deep enough to fill up very large tubas. Shown in second photo.