RE: M_Boats: boom vang attachment--what's it called and where do I find it??

I use an eyestrap, fixed by two machine screws to an aluminum slug located near the base of the mast in the sailfeed, to attach my boom vang. I've thought about switching to a bail, but I don't like the idea of drilling another through-hole in my mast. Anyway, I've lost the slug. I just saw the darn things advertised somewhere, but can't find them again. They come with two holes for purposes like mine, and a single hole, probably to serve as a boom stop. Anybody know what I'm talking about? Tom Smith & Jane VanWinkle M15/345--Chukar M17/064--Unamed