New and high quality. Professional guitar and With volume, , middle, treble, pres control knobs. LCD display, easy to read. Low battery check LED. Auto and manual tuning mode. Powered by 6F22 9V battery (No Battery) Principle: the vibration of through the piezoelectric strip, drive it with , input it to the computer, amplify the signal through the circuit board, and output it to the speaker. This is an active . 1. Frequency Response: 20Hz~20KHz 2. Control Range: : +/- 12dB at 60Hz Middle: +/- 12dB at 500Hz Middle 2: +/- 12dB at 1.2KHz Treble: +/- 12dB at 3KHz Presence: +/- 12dB at 8KHz Mid2. Control: 600Hz~2KHz 3. Tuning note: Chromatic/Guitar Mode 4. Chromatic & Guitar Tuning Mode(7B/6E/5A/4D/3G/2B/1E) 5. Pick-up: Piezo Ceramic Pick-up Colour:black Material:Plastic+Metal Size:9.8 x 5.5cm Package Contents: 1 x 8 x screws 1 x wire clip 1 x stick 1 x battery box 1 x strap Only the above package content, other are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.