The Superman Symbol 316L Surgical Steel Stud Earrings are based on DC Comics Man of Steel. The Man of Steel on super fancy steel earrings? That's pure marketing genius right there - we have a combination of Einsteins and Teslas back here! Where was I? Oh yes! Talking about the Superman Symbol 316L Steel Stud Earrings. These puppies are blue earrings with the always required red and yellow Superman symbol! Up, up, and away!316 Stainless Surgical Steel is the preferred steel where bio-compatibility is required (such as body implants and piercings). The L means that the carbon content of the alloy is below 0.03 percent, which reduces the sensitization effect. 316 steel has .08 Max carbon content while 316L has a .03 Max carbon content. Stainless steel does not contain, corrode, or rust as easily as ordinary steel. Though it will not oxidize or turn black, it is still not stain-proof.