This is a Guyatone PS-003 compressor effector. It has been cleaned and tested. Both adapter and battery operation have been confirmed. There are some scratches, but there are no issues with use. Instant purchase is OK. Thank you. Guyatone PS-003 compressor effector, equipped with LEVEL, SUSTAIN, and BRILLIANCE controls. - Model Name: PS-003 - Brand: Guyatone - Type: Compressor - Controls: LEVEL, SUSTAIN, BRILLIANCE - Connection Terminals: Output terminal Thank you for viewing.