Gleaming Classic sterling silver earrings. My large Button earring is a hollow half sphere of gleaming sterling silver which measures 3/4 inch (18 mm) in diameter. The large version has the French back (Omega clip and post) for maximum stability and comfort. The photo shows all three of my Button earring sizes for comparison. The Medium 5/8 inch (15 mm) and Small 1/2 inch (12.5 mm) Classic Button earrings have post backs.