Agreed.. a link would be nice..
Other than that there is no such thing as an HD antenna of any format. There is also no such thing as an antenna that's rated for some arbitrary distance, like "50 Miles". That's nothing but sales hype to lure in those not knowing any better.
Distance depends 100% on the power at the transmitter, height of the antenna, it's radiation pattern, topography, what else is in the way, like trees, and the sensitivity of your TV. THEN we can talk about this antenna you're looking at. If you have people in the area that can see local channels, talk to them about what they're using.