String Tuner System mounts to the 39inch Classic Guitar. Addresses frustrating tuning issues found on many guitars. String Tuner System Design attaches to the head of your guitar and corrects the angle of the strings as they pass through the nut. This designed, all metal, anodized, so you know it is designed well and durable for many years of trouble free service. This classic guitar mod greatly improves the tuning stability of your guitar and it looks fantastic doing it! size: 51 x 22 x 11mm Material: Metal colour: black Package Contents: 1 x String Tuner System Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.