- Brand: YAMAHA - Model: 32C4 - Type: French Horn Mouthpiece This is a standard size mouthpiece. It has a few scratches, but is in relatively good condition. The following is quoted from the YAMAHA website: Retail price: 7700 yen Part number: HR-32C4 Rim inner diameter (mm): 17.48 Throat diameter (mm): 3.98 Features: This model has a larger rim inner diameter than the 30C4, allowing for a louder sound. It has a relatively flat rim of moderate thickness, and is particularly good for articulation.