This tuner was designed for use with acoustic guitars, ukulele, and other acoustic instruments. This chromatic tuner can be easily concealed within the instrument's soundhole for discreet tuning. This tuner has a non-marring mounting clip, is easy to install, and uses a sensitive piezo transcducer to sense the vibrations from the soundboard for accurate tuning. The tuner's diisplay is multi-color, easily allowing you to see the note and how close you are to being in tune. This tuner can even be calibrated - A435 to A445HZ!