REVOL KNOCK TREMOLO I haven't had much chance to use this since I bought it, and it's been stored at home. There are some light scratches on the surface, so I've marked it as "slightly scratched or dirty," but overall it's in good condition. Box, instruction manual, rubber for the back cover, drawstring bag The rubber is not yet attached to the back cover. Manufacturer: Revol effects Effects pedal Tremolo