This is a tremolo/vibrato pedal from EarthQuaker Devices. It has only been used indoors, so I think there are no noticeable scratches or stains. Operation has been confirmed. The following is product information. A modulation pedal that recreates the sound of an optical vibrato effect with an original circuit. The Voice and Throb controls create a three-dimensional sound with a rich, undulating effect. Intensity and Rate controls allow you to adjust from a gentle, wave-like sound to a rapid, helicopter-like sound. Equipped with a Level control, it also supports volume settings within a band. ■ Guitar effects pedal ■ Optical vibe ■ Controls: Intensity, Voice, Rate, Throb, Level ■ Power: DC9V～DC18V adapter (sold separately) Type... Electric guitar