Gotoh Mini 510 Locking Tuners (Black) 6-In-Line SGS is the smaller model of SG510 series and use a 18:1 gear ratio The SG510 series has evolved through improvement without compromise at any stage and come equipped with a considerable application of high-technology as standard With the improvement of precision fitting gears, marvelous touch on playingthey have gained a considerable reputation and are trusted as the No.1 machine head by many musicians all over the world Mounting hardware included.