Thank you for viewing. This is a listing for the main unit only. The battery will be shipped empty. It features an easy-to-read meter and three lights (LEDs) for accurate tuning. "Digital Cent Display" allows you to check the pitch deviation numerically, enabling more precise tuning. It has a reference tone generation function. The built-in high-sensitivity microphone can also be used for tuning acoustic instruments. It is convenient for tuning electronic instruments that use amplifiers and silent instruments. It is equipped with an auto power-off function that automatically turns off the power after a certain period of time, and a memory function that eliminates the need to reset each function even when the power is turned off. Using the separately sold pickup microphone (Seiko STM20/STM10) allows for reliable tuning without being affected by ambient sounds. The energy-saving design has significantly extended battery life, three times longer than our conventional models (approximately 200 hours when A4 is tuned). ■Size: 105.6(W) x 64(H) x 17.7(D)mm, 90g (including 2 AAA batteries) ■Modes: Auto, Manual, Sound ■Measurement Range: Guitar <7B, 6E, 5A, 4D, 3G, 2B, 1E>, Bass <LoB, 4E, 3A, 2D, 1G, HiC> ■Reference Tone Generation: Guitar <7B, 6E, 5A, 4D, 3G, 2B, 1E> (one octave higher), Bass <LoB, 4E, 3A, 2D, 1G, HiC> (two octaves higher) ■Reference Pitch: A4 = 435-446Hz (in 1Hz increments) ■Terminals: Input, Output