RE: "WHAT is this?"
With all of the modern day gadgetry for compounds, I fail too see much of a advantage. With bows shooting at speeds over 300 fps with carbons, mechanical heads, drop-away rests using shorter arrows in the 26" range, how would shooting thru this tube be an advantage? You still got to aim the thing, guess distances, right? I know the lighter the arrow, the flatter the flight, but if you get too light then where is the penetration?
Looks to me like another gimmick for the archer to waste his money on.
Just my opinion...
GB
Smack 'em where it hurts!