With the goal of keeping your instruments sounding performance-ready at all times, the CT20 is packed with comprehensive tuning capabilities. It allows a wide range of calibration from A410-490Hz, while its smooth, real-time display provides precise and accurate tuning. The unit offers chromatic, guitar and bass tuning modes, as well as a built-in mic for tuning your instruments via audible sound and a piezo (clip-on) sensor that calibrates by vibration. The CT20 also features a flat/drop tuning/transposition setting that allows you to easily tune down your instrument.