Please read the following description and profile before purchasing or commenting. [Manufacturer] Behringer [Model Number] BDI21 [Included Items] None (body only) This is a preamp for bass. - Operation confirmed with 9V battery and adapter. - Output from output and cannon output confirmed. - Knob operation confirmed. - Ground lift switch operation not confirmed due to lack of testing environment. There are minor scratches and scuffs from use, but no noticeable damage. Ships via Yu-Yu Mercari. No price reduction considered.