Which set-top box is for a 4K TV?

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[blockquote]Patrick Swaisy said:

Which set-top box is for a 4K TV?

[/blockquote]

Any set-top device that connects via some medium that the TV will accept is “for” a 4K TV. If you mean, what kind of device will supply actual 4K content to a 4K TV… that’s a slightly different question.

Most cable and satellite providers don’t actually supply 4K content as yet, or if they do, they don’t supply 4K (3840x2160) linear channel content. A few (like Comcast, DirecTV, Dish Networks, and maybe a few others) do have set-top boxes that provide 4K on-demand content (at least, for some subset of their content; consult their website and/or a representative to find out specifics). You’d need one of a very specific (and narrow) list of devices they have on offer to support the content they do have.