The Mooer MEP-BT Baby Tuner is a high precision chromatic tuner in a micro size pedal. It is accurate to +/- 1 point and shows the note being tuned and indicates in tune. Works with most Electric or Electro-acoustic instruments including seven string guitar and five string bass. Display uses 108 high brightness LED’s and is visible even in strong light/sun. Very small and compact design. True bypass switch. DC 9V.