It really works!

I'm guessing: it didn't. I mean, it's possible there's some rudimentary crystal set inside, and if you string a line between yourself and your friends they can "hear" you, but the use of the term RADAR makes me a leeeetle bit suspicious.

Get on the road to popularity! Also, get on the road to realizing that the phrase "money back if not completely satisfied," found on so many ads, can be conspicuous by its absence.