eSynic HDMI Splitter
For our lobby displays at work, I have one setup at the entrance of the building where two TVs are back to back to each other. I originally had an Apple TV at each one (running kitcast). After hearing about this product, I ordered it and was able to repurpose that 2nd Apple TV elsewhere.
There are three inputs: input in, output 1, and output 2. They are all female plugs, so you’ll need some HDMI cables to go with it.
You can order it on Amazon for $15.95.