This Korg tuner can be used to tune up almost any instrument. A4 can be set to one of eight reference pitches between 438 and 445 Hz with the calibration button. It also has 1/4 inch plug sockets to use as a pass-thru device so that it can be used to tune electric instruments such as guitars. Owner's Manual is included. Takes one 9 volt battery, included. Cash only, no trades or exchanges, no shipping. Pick up only in Orem or American Fork.