This set of 3 x 3 Hipshot Grip Lock Locking Tuners are high quality with a lightweight open back design and a 1:18 gear ratio for a good balance of tuning speed and precision. Locking tuners speed up and simplify string changes and eliminate string windings round the tuner post. The included Hipshot Universal Mounting Plates allow screwless installation of the tuners meaning you don't have to worry about the attachment screw holes lining up or having to drill new mounting holes. The plates mount between the tuner and the headstock and have tabs on to stop the tuner rotating, the tuners nut on the headstock face holds the tuner and plate together.