This is the BOSS GS-10 Guitar Effects System. It is equipped with the COSM system, which is also featured in the GT series, and comes with many usable preset sounds! The unit itself has a built-in speaker, so you can enjoy it even without an amplifier ♪ The easy-to-understand control panel makes it easy to create sounds intuitively. Sound output has been confirmed through the speaker and headphone jack. There is no crackling, and the operation is good. It can also be used as an audio interface, but it has not been checked due to lack of confirmation of its operational status. It has been initialized to factory default settings. I believe this is a unit that can still be used! Don't miss this opportunity ♪ This listing is for the main unit and adapter. As this is a used item, there are some minor scratches. Thank you for your understanding before purchasing.