Musiclily Acoustic Guitar 3 Band Preamp Amplifier Equalizer EQ 505R Pickup Piezo For Using Under The Saddle Pickup For Acoustic Guitar Does Not include a battery. Pre-Wired For Easy Assembly. Supplied With A Battery Box And One 9V Battery, And One Saddle Pickup Bass Control: 12Db At 600Hz. Middle Control: 12Db At 600Hz. Treble Control: 12Db At 2.2Khz. Size: About 40 X 95 X 58Mm. Package Included: 1 Set EQ, A Battery Box ,One Saddle Pickup.