-french wires are for pierced ears stamped 925 sterling silver no extra cost. -lever backs are for pierced ears stamped 925 sterling silver, secure setting that clips in the back extra 3.00 per pair. -clip on are for non-pierced ears are surgical steel hypo-allergic extra 2.00 per pair. -post studs are for pierced ears stamped 925 sterling silver extra 2.00 per pair.