The 4 band equalizer is for acoustic guitar, it Features clear LCD display, with note and pitch button, notch function, you change voice frequency by the?bassmiddletreblepres knob, this equalizer helps to modify the sound and provides you more perfect tone. Features: 4 band equalizer suitable for acoustic guitar, perfect for modify and perfect the sound. Rotating the bassmiddletreblepres, free for you to change voice frequency. With note and pitch button, notch function and volume control knob. Bright and clear LCD display, easy to read. Powered by 9V alkaline battery(not included), with low battery indicator. Comes with pickup line, mounting screws, sticky plate and cable tie, convenient to install. High sensitivity and durable quality, it helps you make perfect performance. Specification: Main Material: Plastic Bands: 4 Input Impedance: more than 15MOhm Frequency Response: 20Hz--20KHz Control Range: Bass: +-12dB; Middle: +-12dB; Treble: +-12dB; Presence: +-12dB Pitch: 433-447Hz Interface: XLR Connector Plug & Guitar Amplifier Jack(6.35mm) Power Supply: 9V Alkaline Battery(Not Included) Item Size: 7.4 * 5.2 * 3.9cm 2.9 * 2.0 * 1.5in Item Weight: 81g 2.9oz Package Size: 12 * 8.5 * 6cm 4.7 * 3.3 * 2.4in Package Weight: 158g 5.6oz Package List: 1 * 4 Band EQ 1 * Battery Box 8 * Mounting screws 1 * Pickup Line 1 * Sticky Plate 1 * Cable Tie Note: The battery is not included.