The instrument accessory knurled head screw is designed to meet the needs of musicians who demand reliability and precision. Its sturdy construction and easy-to-use design make it an for securing keys on various brass instruments. Whether you're a student or a professional, this accessory ensures your instrument performs at its best. Features -Color:Golden -Material:Metal -Size:0.79X0.79X0.65cm/0.31X0.31X0.26in -Enhanced key stability: the horn knurled cap ensures that the keys remain firmly in place, enhancing the stability of your performance -Noise reduction design: the triple flat key structure significantly reduces key noise, providing and more refined musical experience -For horn: designed specifically for horns with four keys, it offers a precise fit and effortlessly enhances your instrument's capabilities -Easy to adjust: the upper bass horn key fixing nut allows for simple installation and quick adjustments, meeting the demands of various performances -Craftsmanship: this instrument accessory is crafted for durability, ensuring it enhances your performance for years to come Package list: 1 x french horn rotor screw