Hi there,
Actually, this is a HDMI over IP (TCP/IP) transport device. We ship HDMI over IP from Just Add Power to the trade in the UK. These particular fellas are based on a Chinese chip that uses a JPEG motion compression system.
They are built by a reputable chinese factory, but who'll sell to anyone. So these are everywhere right now. Whilst the product has quality around the central chip, it's the central chip you need to worry about.
They use about 30mbps of bandwidth and they work over certain powerline adapters in our tests. Not all work, and you'll probably waste money finding a pair that do.
BEWARE - If you use these on powerline, you'll be able to use nothing else. It might work if you use these on a pair of powerlines from one manufacturer and ordinary data on another manufacturers type of powerline. Powerline isn't a set standard and it's why manufacturers devices don't work with eachother.
BE MORE AWARE - The taitatech chip these things are based on uses a motion jpeg system. The result is that you'll lose the odd frame of video from time to time. Resulting in a stutter. It's EXACTLY why the HDMI over IP from Just Add Power in it's 2nd generation is as far away from this as possible.
BE EQUALLY AWARE - Your picture quality will take a dive. The amount of compression is high on the taitatech chip. Shading goes bad.
I have two pairs of these in my workshop and whilst they are cheap, they have inherent issues. My advice, avoid. Unless you know the issues and are happy with them being that way.
Many Thanks!