BQLZR OPUS-III 3 Band EQ Piezo Acoustic Guitar Preamp Pick Up Tuner Under the saddle pickup for acoustic guitar<br> Pre-wired for easy assembly<br> 3 bands plus volume control<br> Supplied with a battery box<br> Connecting wire with 2.5mm plug included<br> Low battery indicator This brand new Opus III pick-up equalizer system with 3 bands can be easily fitted into your acoustic guitar and it is essential to electrify and amplify their sound. Specifications:<br> Bass Control: 12dB at 600Hz<br> Middle Control: 12dB at 600Hz<br> Treble Control: 12dB at 2.2KHz<br> Input Impedance: 10MO<br> Frequency Response: 20Hz - 20KHz<br> Power: 9V alkaline battery (not included)<br> measurement of the Preamp<br> width:48.59mm<br> length:92.36mm<br> <br> Package Included:<br> 1 x Pre-Amp plus pickup<br> 1 x Connecting wire with 2.5mm plug