Up for sale is my MXR-M83 Bass Chorus.  This unit was purchased a couple of years ago but never used and still includes the original box as shown in the picture.  Includes controls for bass, treble, intensity, rate, & width.  Other features include crossover switch as well as a flanger switch.  You can go from a mild effect to wild with just a simple adjustment of the controls.  Runs on 9v battery or AC adaptor, not included.