Features: Acoustic guitar piezo pickup and preamp system, sensitive enough to capture sound quickly. Stick the preamp onto the sound hole inside, easy to install and no need to cut a hole. 2-band EQ: Bass--add depth and weight to the guitar sound; Treble--add or take away the higher tone. Phase switch for improving bass response at low volume and suppressing feedback at high volume. With volume control knob and low battery LED indicator.