Specifications: Material: Zinc Alloy Color: Black Golden Gear: All Copper Gear Ratio: 18:1 Name: Yibuy Size: 3.75x3.45x3.3cm / 1.48x1.36x1.3 inch (LxWxH) Weight: 193g Features: 1. Open style machine heads with heavy duty internal gear. 2. The guitar will not go out of tune if the screw post is locked when tuning properly. 3. Tuners have an 18:1 gear ratio, sealed lubrication, metal knobs, and threaded peghead bushings. 4. Tuners use a rear thumbscrew to secure the guitar string, reducing tuning issues at the headstock. 5. Suitable for Classical Guitar Package Content: 6 x Tuning Pegs 12 x Screws Each item is quality checked with a unique Manufacturing Part Number label on the inner package to confirm authenticity. For any questions, please contact the seller and provide the MPN label information.