Features: Pickup, tuner and equalizer system for acoustic guitars. 4-band EQ (BASS, MIDDLE, TREBLE, PRESENCE). With LCD display, easy to read the tuning information. With volume control knob and low battery check LED. Ideal for acoustic guitar players to improve the guitar sound. Specifications: Material: Plastic Control Range: Bass --±12dB at 80Hz Middle --±12dB at 800Hz Treble -- ±12dB at 15KHz Presence -- ±12dB at 3KHz A4 frequency: 440HZ Tuning Range: A0(27.5Hz) - C8 (4186.01Hz) Power Supply: 1 * 9V Battery (not included) Item Size: 6.5 * 5.8 * 2.5cm / 2.6 * 2.3 * 1in; 6 * 3.5 * 5.5cm / 2.4 * 1.4 * 2.2in Item Weight: 90g / 3.2oz Package Size: 10.5 * 7 * 7cm / 4.1 * 2.8 * 2.8in Package Weight: 115g / 4.1oz Note: Battery is not included.