I'm giving the sky rear view camera 5stars
First off its packed nice. It looks good quality just by picking it up and feeling it you can kind of feel the quality.

Great quality considering the sensor size.  Decent low-light performance, but not perfect.

Came well-packaged with everything needed.  I like that the front bezel screws off and you can remove the mounting bracket.  I did so and reversed the bracket to better suit the mounting position I wanted.  Recommend having the mounting bracket off by itself when securing it so as not to damage the camera.  With the included video cable, I was able to run it along the driver-side frame of my F350 (Supercab w/8ft bed), up through the pass-through under the carpet, just below the pedals, and still had several feet left of slack.  The camera itself has about 1-2 ft of video cable as well.
Video plug on camera end is female, and the the extension is male/male.
I did not hook power to my backup lights.  I have them on switched power so the camera will be on all the time while ignition is on.  This is not the intended use of them, but this is what I wanted.
After you have it mounted you'd want to adjust the camera to suit your backup needs.  The guidelines are for reference and depending on the angle of the camera can vary in actual distance.  I have mine adjusted so that the bottom red guide gives me about 4-6 inches from object.
For the price, I'm very happy with the build quality, picture quality, installation, and parts.

Works perfect pretty bright at night awesome in the day so far so good

This works better than the one that costs 2X the amount. Very crisp image, great at night.

Great!

I'm surprised at the clarity, honestly didn't expect much from it. its not as much as a wide angle as my factory one in my truck but at $20 its very hard to beat. i bought 2 and gave one to my buddy.

This camera is very discrete and the grid lines are helpful.

This is an excellent little camera.  Very small, screws easily onto the bottom of the rear fender plus a little bit of wiring to connect to the reversing light power leads, I used some small quick-splices to avoid having to strip and solder.  Daylight performance is great and night time performance is also surprisingly good.  Very good value.

It has good picture for the price.