New and high quality. Professional guitar and bass tuner With volume, bass, middle, treble, and presence control knobs LCD display, easy to read. Low battery check LED Auto and manual tuning modes. Powered by 6F22 9V battery (battery not included) Principle: Picks up vibrations through the piezoelectric strip, transmits signal to the host, amplifies via the circuit board, and outputs to the speaker. This is an active pickup Frequency Response: 20Hz~20KHz Control Range: - Bass: +/- 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 Tuning note: Chromatic and Guitar Mode Chromatic & Guitar Tuning Mode (7B/6E/5A/4D/3G/2B/1E) Pickup: Piezo Ceramic Pickup Color: Black Material: Plastic and Metal Size: 9.8 x 5.5cm Package Contents: 1 x Pickup 8 x Screws 1 x Wire Clip 1 x Pickup Stick 1 x Battery Box 1 x Strap Only the above items are included; other products are not included Note: Lighting and display differences may cause slight color variations between the image and the actual item. Measurement error allowed is +/- 1-3cm