Originally Posted by
WhyFi
Are you asking in earnest because you're genuinely interested to know or are you asking because you're looking for a "gotcha!" to illustrate how the doodad isn't worth the time and money?
You should argue about a false sense of security after you've ridden with one.
I'm asking because I want to be a safer rider and know how this device adds to the equation. If all it'll do is signal when any car is approaching from behind, I don't see how it'll benefit me. OTOH, if the device can warn about cars that could pass too close, this would help greatly.