These are silver metal with a genuine Swarovski 1028 xillion chaton rhinestone set in them. They come with the backs and can be set with The Crystal Applicator Tool or a Crystal Rivet Setter 8100-00 and Poundo Board #3461. See instructions under our faq "How do I set Rhinestone Rivets?". The measurement from the back of the shank to the front of the stone is 8 mm long. The length of the shank by itself is 4.6 mm long. The diameter of the shank is 2.6 mm wide. The diameter of the top of the rivet is 6.9 mm wide.