The Grover Sta-Tite 97-18 series tuning machines offer smooth and precise tuning for your electric or acoustic guitar. With an 18:1 gear ratio, these open-gear tuners provide quick, accurate tuning and rock-solid stability once locked in. The stylish die-cast plates and amber acrylic buttons give your guitar a classic look while the 22/64" post hole and .074" maximum string gauge ensure compatibility with most standard guitars.