I have been watching these for a while, actually Saunders Archery made this type of product years ago but they just never caught on. Here is a picture
I am not sure how well they really work, I have a Mathews with the string supressors & it does work fairly good at keeping the strings queit. I don't think it needs string silencers at all. I am sure the STS and the other products work ok, someday I will have to try one but I just feel they are over priced for what they are.