I purchased this item used previously. I am selling it because I no longer need it. Please ask if you have any questions. 2-input, 2-output USB audio interface. Phantom power compatible, also equipped with monitoring function. - Brand: M-AUDIO - Model Name: M-TRACK DUO - Number of Inputs: 2 - Number of Outputs: 2 - Phantom Power: Yes - Monitoring Function: Yes - USB Connection: Yes The original outer box is also included. The included documents are only those attached in the images. USB Type B (unused) is included. #DTM #AudioInterface