This is a very detailed skull belly button ring with a 316L high grade surgical steel shaft and a .925 sterling silver skull and cross bones design. The skull has jewels for eyes in your choice of clear, light blue, dark blue, green, purple, or black. The externally threaded top ball size is 5mm. This navel ring measures 14 gauge and 10mm- 3/8 of an inch. Entire piece is nickel free.