Electro Harmonix Lester K Stereo Rotary Speaker Pedal Rotary speaker emulation at its finest in a compact, easy to- use package. Stereo outputs provide a lush, realistic sound with either stereo or mono inputs. Tube-style overdrive is variable and the speaker balance can be fine-tuned. Switch between adjustable Fast and Slow modes to achieve that iconic sound when the big cabinet ramps up to speed and down.