Suitable for both guitar and bass. When used with low gain and flat EQ, it acts as a saturator, improving the blend with the backing track without altering the sound's character. Boosting the EQ provides a slightly refined SansAmp-like nuance. Increasing the gain results in a highly distinctive distortion. At full gain, you can create distortion similar to clipping. The wide range of the EQ allows for aggressive sound shaping in combination with the gain. There are some minor scratches on the surface, but there are no operational issues. This is a listing for the unit only. I believe this is a model that doesn't often appear on the market. Don't miss this opportunity. The following is a reprint of the manufacturer's description: "Surveyor" is a drive pedal that reconstructs the cult classic rack-mount preamp "Instrument Voicing Preamp (IVP)" as a compact pedal. Speaking of IVP, it's "that" sound, the symbol of noise rock, played on an aluminum-neck guitar. However, this unit is not limited to that, and can create a wide variety of textures and tones that transcend instruments and genres. Its features include a unique distortion circuit using a transformer and an EQ placed just before it. By controlling the distortion range, you can achieve both sharp, metallic drives and fuzz sounds with completely saturated low frequencies as you wish. You can also use it as a preamp with reduced gain for a more subdued sound, or crank it up and plug it directly into a mixer to witness a truly destructive sound. Please experience the countless niche and unique distortions with your own hands.