So I bought it for my Ram 2500 with tires rated for 60psi. This will fill them up, but it takes forever as the compressor they turn on is very weak. It's so bad the instructions literally tell you to update it. So bad I had trouble filling the donut with sea swimmers. As for its functionality and all the wiring etc, it was quite simple and easy to do. The pressure switch works great, so don't worry. It has the potential to be really good, but it MUST be replaced with the compressor itself.