These are ion plated over 304 grade stainless steel, strong and sturdy and resistant to turning or tarnishing. The ion plating gives a unique color changing rainbow effect. They measure just under 5/8 inch (15mm) in diameter. Wear as is or easily add charms or your own unique dangle designs to customize. If you would like to add beads or charms they must have a hole 1.7mm or larger to fit on the earring. Package of 4 (2 Pair)