Actually HD video quality was what I saught after when I found that info.
I think the size of the video is related to what pixels the camera is setup for. While clarity is based on the coax or fiber optic cable.
So, we all have not soo good clarity. Anyone remember that company that was all the rave with their replacement tailgate backup boasting clarity? That may be a better option then the ebay deals. I have the ebay on mine and yeah, clarity isn't like watching 4k, but will do while I reverse.