Boss AD-3 Acoustic Instrument Effects Processor Compact acoustic instrument processing pedal developed exclusively for acoustic-electric guitarists Footswitchable Bi-Stereo chorus offers split-frequency processing (Low and High) for natural, smooth chorus effect Studio-quality Reverb provides clear, deep reverberation specially tuned for acoustic guitar Newly developed "Bottom" and "Top" controls offer variable tonal shaping to eliminate "dry" sound from piezo pickups and add rich, resonant lows and brilliant highs Special Guitar Amp output provides proper impedance and tonal balance for connection to a guitar amp