This is a DOD overdrive pedal, capable of extreme distortion when the DRIVE knob is set to 9-10. It's a MADE IN USA gem. Operation has been confirmed with both a 9V battery and an AC adapter. There might be some crackling, but it seems to be at a relatively unnoticeable level. The battery cover is missing. According to online research, it appears to be an early model from around 1987. *When using an AC adapter, a mini-plug conversion adapter is required. The effect pedal itself has minor scratches and dirt (see photos). We are looking forward to your purchase if you understand that this is a used item. Thank you for your consideration.