Thank you for viewing. This is a rack-mounted effects unit, the ZOOM STUDIO 1204. I received it and used it a few times, after which it sat unused in my rack. I have performed a basic operational check for this listing. Sound output was confirmed on both L and R channels, and effect switching worked without issue. The input also had no noticeable crackling. I have not performed any further detailed checks. - Included items: Instruction manual, AC adapter The AC adapter is included, but it is not the original one, so I am using a different one. It is currently working without problems. The adapter's connection port feels a little loose. The power would sometimes cut out if I fiddled with it. I used it in a rack with the power plugged in constantly, so it wasn't a problem for me. As it is an old item, there may be some age-related deterioration and wear. Please understand this before purchasing.