Yukon DSAS(Directional Sound Amplification System)

I was searching through internet for cheap(like where I would find those) weaver posp scopes when I came across whith this product:

http://www.eastwavescope.com/index.php?event=description&gr_1=11&gr_2=25&item=116&lang=en

Apparently you can listen what peopl..... animals are doing from 100m away. Since it is weaver it could be easily attached to scope. It could be quite awesome in bigger scenarios where you have real recon missions and you could use it to get some important information(listening enemy commander etc.)

Does anyone in here have any experience whith this kind of a things?