This is a Yamaha French horn mouthpiece, model 33C4. This mouthpiece features an enlarged throat diameter, gold plating, and DCT treatment. The 0.1mm enlargement of the throat diameter improves breath flow and increases the fullness of the sound. It appears to be in excellent condition with minimal signs of use, possibly due to the low number of times it has been used after gold plating. Please refer to the photos for details.