Counterfort-mount. 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. You can switch from right to left and vice versa by yourself. Please unscrew the screw from the worm gear, lift the worm gear, turn around the worm screw with the button, place the worm gear again and tighten the screw.