The D'Addario 6-in-line Auto Trim Tuning Machines are precision tuners that automatically cut the excess string while changing strings, eliminating the need string clippers making string changes easy and fast. The 18:1 ratio worm gear constructions ensures greater precision than standard tuners and ensure tuning stability even during the hardest playing. Includes 6 tuners and mounting hardware. Chrome finish. 6 in-line setup for instruments that have all 6 tuning machines on the same side of the headstock.