Whether you are making earrings, or you have lost the backs to your favorite pair, these best-quality sterling silver earnuts are just what you've been looking for. the larger diameter will help keep heavier earrings stable. swirl design adds a lovely detail to your post earrings. measurements: 9mm diameter, 4mm deep. will accommodate a 20 gauge (.032mm) standard earring post. quantity: you get 4 earring backs (2 pairs).