This is for the YAMAHA Flugelhorn FH83150-2, but can also be used on other models. These screws were introduced on Twitter by Masato Honda and became a hot topic. These are the mouthpiece receiver screws used on the YAMAHA YFH-8315G Flugelhorn, supervised by Wayne Bergeron. The newly designed screws have a barrel shape, making them easier to operate and adding weight, which provides stability and a comfortable playing feel in all registers. Furthermore, the use of phosphor bronze material achieves a distinctive tone, characterized by brilliant high frequencies and rich mid-range tones. Because the screw pitch is M4 x 0.7, it can also be used for current YAMAHA saxophone neck screws and Wood Stone or JLV ligature screws! However, please refrain from using this product on instruments or ligatures with different screw pitches. Forcing the screws can damage not only this product but also the screw receiver. Thank you for viewing.