Radio for GMC Yukon Tahoe Suburban 2004-2006

Radio for Tahoe Yukon Suburban 2004-2006 in its condition, my grandfather gave it to me before they installed the navigation system in their car. I don't know anything about it. Before they installed the radio and the new system, I don't know if it was working or if there was anything wrong with it at all, and now I don't know if it's working or not. The requested price is 550﷼, non-negotiable. Those interested please call.