5 Pairs of Surgical Stainless Steel Aurora Borealis Crystal CZ Stud Earrings 3,4,5,6, 7mm Amazing light refraction that gives these studs a true Aurora Borealis look High Quality Stainless Steel (316L) design for backs and posts 5 Sizes from 3mm to 7mm Looks amazing in person (the light refraction is hard to capture in a photo). Note that even 316L stainless contains about 5% nickel; severly sensitive individuals may feel irritation.