10" or close to that I don't want to go smaller but no more than 12". I am going to mount it on the roof of a ford explorer 2001. It's going to be hooked up to a xbox. I have looked on ebay but everything I find has no brand name. Are these safe to get or is there a more reliable brand out there or website to buy from? I don't need a built in dvd player just a fold down screen. thanks!