tip: always include a link 
I think you’re not looking for a “video amplifier” but for a “powered video splitter”?
I’ve seen products like the one you’re asking about when we were also looking for video splitters. As far as i can tell that’s a product meant for vehicles…for example a bus with a single video source, and 4 video monitors to show movies to passengers. I guess you need to power it, so if you go for it make sure you have a proper power supply.
We don’t know anything about cars and their power supplies so we bought one of these video splitters: Amazon.com
plus another one, at the same price, with 8 outputs. They come with their power supplies which are standard anyway. They have been working without issues for about six months now.
If you get one of this be careful - most of these products aren’t 1-to-many splitters, but the other way around (many-sources-to-one-video-input switches) and sometimes there are mistakes in the product name and description…so double check pictures and description.
also, we confirm the following