If your tv is not 4k you would only get 1080p or whatever resolution the tv has in which you are plugging the Roku into. So if it is a 720p tv, you get 720p. A 1080p tv is 1080p, etc. Hope this helps. You can still buy the 4K box incase you upgrade your tv one day though. It will still work because the Roku automatically senses what your tv‘s display is capable of producing and adjusts accordingly. That is a pro perk to the newer Roku lineup.