The Medallions are made of some kind of metal, and are exact copies/looks of factory medallions. They are a bit larger and have a more silver finish look to them. When I first saw the grips for sale, I had my doubts, but was very pleasantly surprised when I received them. I've been checking on the company that makes them, but have not seen anymore for sale lately. I would definitely buy more should some others come up for sale. To answer the question about how they fit so well, I'm sure they have metal gun/gun frame copies similar to what holster makers use to fit their grips to the respective grip frame sizes.