Thanks for posting here in the Community!
To clarify, are you referring to Roku Streambar Pro or Roku Streambar?
For both of the audio devices' dimensions, it can be found on our website. Just choose the Streambar you're interested in then scroll down to 'Size'.
Both Streambar mentioned above can be used with your TV's built-in tuner and any device connected to your TV, such as a Blu-ray player, game console, or cable set-top box. Just attach a Premium High-Speed HDMI cable, connect your Streambar or soundbar to the internet, and complete the easy setup process.
Check out these Support articles for more information: What is a Roku® Streambar™? | What is a Roku® Streambar™ Pro or Roku Smart Soundbar?
I hope this helps.
All the best,
Roku Forum Moderator