Amazon Fire TV Box to HDMI on TV?

I'm looking at the Amazon Fire TV box and I wanted to know if it has any other outputs besides HDMI? I have HDMI on my main TV, but only RCA connectors on my bedroom TV. I plan on using the same box for both TV's even though I have to disconnect it each time I want to watch on a different TV.

Also, I see that it now supports 4K Ultra HD. Do I need to update the Amazon Fire TV box software to get that?
What color are the RCA inputs on your second TV? Is it component, Red-Green-Blue/YPbPr + Red-White? Or is it composite, Yellow-Red-White?

If it's component, you'll need an HDMI to Component converter.

If it's composite, you'll need an HDMI to composite converter.

As for 4K, that will depend on your device. If you already own one that's HD/1080, I doubt it can be updated to produce 4K, but you'll need to check the documentation from Amazon.