I have never seen these links anywhere and there is really no information out there about these unusual links. I know that they are called "finger prong" links and have an interesting hinged area that closes very tight. This pair is ¾” square with a good luck horseshoe imbedded in the middle of a black glass that is in a gold tone setting. I want to believe it is rolled gold but there are no marks except for “Trade Mark” on underside. It is in very good condition for age but have no earthly idea how they are worn. This is for the cuff link collector that wants a piece of history. Check out the pictures on this very interesting pair.