Buzz's standard piston shaft for Yamaha. Compatible with standard models and artist models. Please check the manufacturer's website for details. I tried it on my 9335NYS BR. It's a mint condition item, only used once for a test play. My personal impression is that it's suitable for those who like a thick and soft tone. ^_^ It changes the sound quite a bit, but it doesn't seem to affect the pitch. It has a good resistance, making it easy to create the tone. Don't miss this opportunity! ✨