The Boss RV-3 is a professional-quality guitar effect pedal capable of producing reverb and delay effects, or a combination of both. The Boss RV-3 offers four different high-density reverb modes plus three delay modes with delay time up to 2,000ms, with a combination of 11 different reverb and delay effects. This guitar effect pedal also provides 4 modes for a simultaneous delay (32 to 1,000ms) and reverb effect using Room 1/2, Hall, and Plate reverb types. The Boss RV-3 offers you plenty of tweaking ability with its Balance, Tone, Reverb Time, and Mode control knobs.