The SG510 series are recognized the world over as one of the top performing super tuners on the market. These feature an 18:1 gear ratio. They have evolved through improvement without any compromises along the way. The come equipped with a considerable amount of high-technology as a standard. With the improvement of precision fitting gears which give a marvelous touch on playing they have gained a considerable reputation and are trusted as the No.1 machine head by many musicians all over the world. These are three-on-a-side. Mounting hardware included.