What PABowhntr said. There are a ton of threads on the STS over on the Archery Talk site, where everyone seems to think it is the greatest invention ever produced by man. I bought one for my Reflex Buckskin. Quite frankly, any improvement it made was minimal at best. That, coupled with the poor e-mail support the company offers, has left me unimpressed with it. However, as I indicated above, there are a lot of people that swear by it, so maybe I'm just one of the few that it doesn't benefit.