Directv Stream Box add additional TVs.

You would have to get additional streaming devices like Fire Sticks, Rokus, or Apple TV’s for each additional TV you want to stream on. You can also get more DIRECTV STREAM boxes for a similar experience you are getting in the main room. There is no monthly ongoing cost for adding a box (granted you don’t get a directv stream box and pay $5/mth paying it off). 

I wish the sales person would have explained that better. I guess he meant you can add up to 20 devices provided you have a streaming device such as a Roku, Firestick or Directv Streaming Box for each TV, or each TV is compatible with the Directv Streaming App. How much would it cost to get an additional Directv Streaming Box? It does work great on our other TV.

@lizdan3 For a Brand New Directv Streaming Box, you can either pay $120 upfront or you can have them charge you $5.00 a month for 2 years or you can get a refurbished box for $49.99.  Both boxes come with a 1-year warranty.