These are a custom item, made especially for us and requested by one of our instructors. These are designed to be linked using 2 jumprings, and then have a stone or other item glued or attached to the pad. The ID (inside diameter) of the tubes on the back is 2 mm, so they will also take 2 mm leather. You could also make a bolo tie with them.
Made in Israel. 10mm By the each.