Are you talking about the thing that had the arm coming off the slide with a rubber stopper on it. If iso Buckmasters (Jennings, North American Archery Group) used to have them standard on the alot of there bows several years ago but now with the advent of the sts, MeanV and others it iss pretty much not produced anymore. I had alot of trouble out of my buddies bows with this type of stopper and every time when we took it off it tuned easy. JMHO