PABowhuntr its a combination antifreeze hydraulic\sound dampening system, the website although not very informative is www.bowmaniac.com . I have heard one post a while back on Archery Talk where the person was saying if you dont mind spending the money they are about the best. (approx $70). I think the construction would probably be on the same idea as the Stealth. Hopefully someone will have tried them out.
BD