This was included when I purchased my wood bass, but I am not using it, so I am selling it. Both the microphone and pickup sides have been checked for sound output and confirmed to be working. It is a passive type that does not require batteries. This is an old item. The knobs have been replaced, so I will include the original dice knobs that came with it. *I am selling this on behalf of a family member. I am not very knowledgeable about this product, so I will answer to the best of my ability. Please feel free to ask any questions.