Whether you are making earrings, or you have lost the backs to your favorite pair, these best-quality sterling silver ear-nuts are just what you've been looking for. Measurements: Part against ear lobe is 5mm wide, 4mm tall. Earring back is 3mm thick. Will fit securely on any standard earring post. Marked .925 on each ear-nut. Quantity: 12 earring backs (6 pairs).