Yamaha oboes are able to produce clear, quality sound with superior intonation through dramatic improvement in the precision and stability of the tube. To deal with the various issues inherited from wooden instruments, Duet + models employ techniques for the formation of a protective layer close to the air column. The combination of special woods and state-of-the-art resin is not just a "Duet" of tradition and technology. It is a real "plus" advantage!