Part Size :9 mm x 9 mm Material: 925 Sterling Silver ( Post Length 9-10mm / 3/8" ) (conversion : 1 inch = 25.4mm or 1mm = 0.0393 inch) (comes with Sterling Silver Butterfly Push Back with 925 Sterling Silver, Clear Silicone Bullet Clutch Ear Nuts for Earring Safety Backs and Little Plastic stored box.)