1、For 39 Inch Guitar: Improve your guitar tone, volume, and sustain with this guitar string tuning system, designed specifically for 39 inch guitars, providing precise tuning and enhancing your playing experience. 2、Metal Structure: Made of excellent metal, this tuning system fits securely on your 39 inch guitar, ensuring stable tuning and improved intonation. Experience a fuller, richer sound with this simple but effective upgrade. 3、Good Performance: This tuning system optimizes string tension, resulting in improved tone, increased sustain, and enhanced playability. Take your playing to the next level with this innovative upgrade. 4、Accurate Tuning: Install it on your guitar to achieve accurate tuning, enhanced resonance, and extended sustain. Unlock new possibilities and enjoy a more satisfying musical experience. 5、Compact Design: This guitar string tuning device has a compact size and light weight, which will not increase the burden on the guitar after installation, suitable for guitar beginners or enthusiasts.