Boss RT-20 Rotary Speaker Sound Processor w/ Power Supply and (2) 10' Guitar Cables Authentic rotary speaker sounds via COSM technology Slow/Fast transition time is adjustable from gradual to rapid change; optional Expression pedal can control speed in real time Onboard Overdrive effects Adjustable mix balance between Treble Rotor and Bass Rotor 4 types of sounds, from standard rotary speaker effects to rock-oriented tones, UNI-V, and more