The black Korg CM-300 is a clip-on contact microphone designed to provide accurate tuning in the midst of even the loudest orchestras or bands. It has a sensitive piezo pickup, which directly captures the vibrations of trumpets, trombones, saxophones, violins, guitars, ukuleles, and more. Through its 1/4" TS connector cable, the CM-300 sends vibrations with improved sound transmission performance to your tuner's 1/4" input, providing the tuner with a precise picture of your instrument's intonation.