The BOSS RT-20 Rotary Ensemble is an innovative rotary sound processor that utilizes COSM-modeling technology to authentically recreate the classic sounds of rotary speakers, popularized by legendary guitarists like the Beatles and Santana. This pedal provides a unique ability to adjust rise time, horn and bass speed, and overdrive effects, allowing for both traditional rotary twirls and modern pulsing effects. Not only does it offer a stunning graphical display of virtual rotors during use, but it also features a guitar/keyboard input switch, making it versatile for various instruments. The RT-20 includes dual output capabilities for true stereo sound and allows users to connect an expression pedal for real-time controls. Its combination of classic simulation and modern technology makes it a valuable addition to any guitarist's setup.