It is hard to review a device that many people take for granted even when they need one. Automotive relays, although complex on their own, are very simple in the grand scheme of things. You provide a power source, a ground, a trigger, and then when triggered, they provide an output.
Overall, I am extremely satisfied with these relays and harnesses. They are built well, easy to use, and do exactly what they are supposed to.
If you are interested in purchasing these relays they can be found here.