MACKIE Big Knob (first generation model). On December 23, 2025, input/output operation was confirmed, and all INPUT / OUTPUT systems were confirmed to be working without any problems. - The talkback function has not been used and is unused. - Purchased approximately 10 years ago, but has been stored in a box for over 5 years. - No significant scratchiness or knob malfunctions are felt. - The exterior has minor scratches from normal use, but is generally in good condition. [Included Items] - Power cable only (Manual is not included) This is a standard model for studio monitor switching and volume control, and can still be used without any problems. Please consider this item with the understanding that it is a used product.