1、Sturdy And Robust: This knobs tuning key is made of excellent quality zinc alloy, plastic and brass material, with exquisite craftsmanship and beautiful appearance, it's a good tool for you to play your musical instrument, which is both beautiful and practical. 2、Multifunctional: This tuning key is multifunctional and is mainly used to hold the strings in place, improve the tone of the strings and ensure accurate intonation. If your guitar tuning pegs are damaged or aged, these new guitar tuning knobs will be your ideal replacement. 3、Easy To Install: This metal guitar tuners machine head is very easy to install and comes with 8 screws, making it very easy and convenient to mount on your guitar for consistent performance. 4、Wide Application:This acoustic guitar tuning peg has a wide range of applications and is useful for tuning guitars, acoustic guitars, folk guitars and other equipment, which is practical. 5、Easy Tuning: This machine head tuner set includes 3 left and 3 right headstock classical guitar tuners for your use, 1 row for left and 1 row for right, keeping your guitar in tune and easy to tune, very practical and convenient.