Based on our M6 series - proven millions of times on bass guitars worldwide! Gear ratio 1:12. - All sealed tuners are lubricated with Schaller special grease for lifetime maintenance-free service. - All parts are precision-crafted and surface-finished, the self-locking drive ensures an even, delicate and steady tuning. - All string posts are made of high-grade brass and fitted into the housing with utmost precision, ensuring the best possible tuning accuracy and wear resistance.