The truss rod wrench is made of quality metal. The long handle allows easier access to the truss rod cavity. Fits most guitars requiring a wrench. Features a nut driver on one end and a screwdriver on the other. Used for adjusting the neck relief, suitable for electric guitar replacement. The 6.35mm (1/4 inch) model fits most folk guitar series and classical guitars. Please check size specifications carefully; longer models may not fit due to length interference with the wood. The 7mm model is compatible with certain Korean and other guitar brands. Choose based on your guitar's actual size. The 8mm (5/16 inch) model fits select American-made electric guitars and ESP electric guitars. Choose according to your guitar's specifications. Color: Silver. Material: Iron. Available Sizes: 6.35mm, 7mm, 8mm. Package Includes: 3 x Guitar Truss Rod Wrench. Other items not included. Note: Lighting and display settings may cause slight color variations. Measurement error allowed: +/- 1-3cm.