YAMAHA Flugelhorn Mouthpiece 13F4 This is a genuine Yamaha mouthpiece for flugelhorn. I purchased it, but it didn't suit me, so I only tried it out. It's in like-new condition. (I purchased it from Shimokura Gakki, but there is some discoloration on the shank from the beginning, as you can see in the third photo. The box also had scratches from when I bought it.) This is a standard model widely recommended for beginners to intermediate players. The inner diameter is slightly smaller than the 14F4, making it easier to play in the mid to high range.