It attaches to the Valentine 1 RD, which is already known as one of the best out there. I hope this guy doesn't underestimate the engineering that goes into a quality radar detector these days. Belscort, Valentine, and Whistler spend millions of dollars and have decades of experience in the engineering. The ability to detect quick trigger, but also having the necessary DSP to filter out false signals being so important, I don't know if this will be a viable product anytime soon.
Edit: It appears he's using a Cobra radar detector. They are a complete joke. This is a non starter if that's what he's going with.
If you have an interest in radar detectors in general, I suggest you check out http://radardetector.net. Read some of the comments on there about Cobras.