This item attaches to a musical instrument using screw holes or adapters, altering the playing feel and tone. It can be installed on models with screw holes in the rotary section, and according to the official information, it is compatible with Alexander 103, Hans Hoyer 801, Paxman M20, and Durk horns. It was also successfully installed on a Yamaha 869. It should be possible to install it on any instrument with M2-sized screw holes. The sapphire version is said to tighten the sound and provide a heavier resistance. When actually attached to an instrument and played, the resistance increased, and the tone also changed. Because the sound tightened, I felt that the volume capacity increased when blowing strongly. It might be too much when attached to instruments with already strong resistance, such as the 103, but it might bring good changes when attached to lighter instruments. 【 Product Information 】 ◆ Gemstone: Sapphire / 2.0mm ◆ Material: Brass / Gold-plated ◆ Size: Head Diameter: 4.5mm Screw Size: M2 Screw Length: 4mm ◆ Included: Nut (Please use it if there is a place to attach it, such as a spring ring.) New price: 8800 yen