The MXR bass compressor is a high-performance compressor designed to improve the sound quality of your bass. It has been used to some extent, but it's in beautiful condition. It works perfectly. Please refer to the photos. This multi-functional MXR bass compressor is equipped with various controls to adjust the sound quality. - Model Name: bass compressor - Brand: MXR - Function: Compressor - Controls: Release, Ratio, Attack, Output, Input - Accessories: Box, Instruction manual Thank you for looking.