I have been dong some research on these. From what reviews I've seen they are supoused to spin the arrow better than any vane or feather on the market. They are all the rage on archerytalk.com and some other sights. I see very little of them mentioned here though. I was debating on trying them . Has any one here tryed them? I know they are only good with drop aways and need a string loop but other than that I don't know alot about them. Thanks Jim