Kmise&reg; 4 Band Acoustic Guitar Preamp Amplifier EQ 7545R Pickup -Flat Presence Control: 12dB at 8KHz Bass Control: 12dB at 600Hz  Middle Control: 12dB at 600Hz Treble Control: 12dB at 2.2KHz  Frequency Response: 20Hz - 20KHz Power: 9V alkaline battery(not included) Pickup dimensions: 10.5(L) x 4.7 (W) x 6(H)cm (4 x 1.9 x 2.4inches) It can be easily fitted into your acoustic guitar and it is essential to electrify and amplify their sound. Under the saddle pickup for acoustic guitar Pre-wired for easy assembly 4 bands plus volume control upplied with a battery box, Low battery indicator Connecting wire with 2.5mm plug included