UnCommon Artistry Sterling Silver Large Fancy Earring Backs (Earnuts) (4) Fancy Sterling Silver Earring Backs (aka "Earnuts") These are large and heavy; intended for keeping heavier/larger earrings in place Measurements: 9mm Diameter, 4mm deep. *Will accommodate a 20 gauge (.032mm) standard earring post. Please see instructions on how to tighten clutch below. Quantity: You get 4 earring backs per sturdy clamshell package (2 pairs). *TIGHTENING THE CLUTCH: If you find your posts are too loose, you can tighten the butterfly clutch with some needle-nose pliers. You need to do this very gently in small steps until the tension is tight enough to prevent slippage, without crushing the shape of the clutch itself.