The "Custom Shop" series exemplifies the high quality KORG tuners is known for. As its latest addition, we introduce a top-level model tuner that can be attached directly to the head of your guitar/bass. The Sledgehammer Custom 100 provides an amazing battery life of approximately 100 hours using only one AAA battery. The easy-to-use shuttle switch is now equipped with an illuminated shuttle light for even better visibility. In addition to a 3D visual meter, you can also use professional ultra-high precision tuning with an accuracy of ±0.1 cents. It's the ultimate high-spec clip-type tuner.