Yamaha Custom Series mouthpieces are sculpted out of choice ebonite, a high-quality hard rubber which offers a deep resonance and tonal qualities similar to those of natural wood. Yamaha has spent years working together with many of the world’s greatest musicians, studying their mouthpieces and discovering ways to improve them. The Custom Series incorporates this experience in the design and manufacture of every mouthpiece in the series. The Custom Series mouthpieces are characterized by a warm rich tone with exceptional clarity. Their accurate intonation and comfortable playability have made them popular with many leading artists.