This set of 3 x 3 Schaller M6 locking tuners have two mounting pins which fit in to holes in the back of the headstock to stop the tuner rotating (in the same format as Schaller Fender tuners), this results in a compact tuner size, they also feature a 1:18 gear ratio for accurate tuning. The Schaller locking system is operated by a thumb screw on the back of the tuner for quick and easy string changes. The enclosed gears feature Schaller's Velvet-Tec and LX6-Lube technologies to ensure the gears mesh and turn smoothly and precisely, backlash is minimised and it also adds durability. The Schaller M6 range of tuners are the world's bestselling and set the standard for fully enclosed machine heads.