Built-in interface. Product priced at 29,800 yen. It's in very good condition, but it might be best to consider it as a junk item. I used it exclusively for vocal recording. The volume has become unstable when recording with a microphone connected. Also, there's occasional crackling noise when adjusting the volume. That's not a major issue, but I'm not very familiar with equipment, so I don't know about recording instruments. Since it's a used item, please understand this before purchasing. Thank you. The following is AI-generated details: Compact mixer with 12 channels, 4-channel USB connection, and built-in effects. - Model Name: Notepad-12FX - Number of Channels: 12 channels - USB Connection: 4-channel USB - Effects: Built-in effects - Accessories: AC adapter Thank you for viewing.