●Suitable for acoustic guitars, classic guitars and electric guitars ●Height: 0.3 inch (8 mm), Upper Outer Diameter: 0.6 inch (14 mm), Mounting Screw Hole Diameter: 0.1 inch (4.2 mm). Please check the size chart before purchasing ●Made of steel, stable and durable ●Easy to install, easy to use ●Package includes: 2 pcs strap pins, screws and washers