Distortion pedal, Stevie Salas model, with LEVEL and GAIN controls. - Model: SHR2 - Type: Distortion - Controls: LEVEL, GAIN - Power: EXT. DC 9V - Input/Output Terminals: IN, OUT Thank you for viewing. I purchased this used from a musical instrument store over a decade ago. The rubber and other parts have deteriorated over time, but each knob functions. The back cover is upside down, but it has been that way since I bought it.