BEHRINGER PREAMP/BOOSTER PB100 Boost the volume and shape the sound of any instrument. Boost up piezo pickups to match regular amplifier inputs Status LED for effect on/off and battery check Dedicated Gain, Bass and Treble controls for awesome sound shaping Runs on 9 V battery or the BEHRINGER PSU-SB DC power supply (not included) First-class electronic On/Off switch for noise-free operation