D'Addario Planet Waves Chromatic Pedal - Slim, small-footprint, accurate tuner is a high-value addition to your setup 32-bit processing and wide calibration range ensure fast, accurate readings High-visability, full-color display is easy to read at all ambient light levels True-bypass wiring for clean, transparent signal transmission when not tuning Aluminum enclosure stands up to tour abuse and enthusiastic performances Can be powered by the included 9V battery or optional 9V external power supply