Threadless Star Top is made of solid 14kt nickel-free Gold with durable 316LVM ASTM F-138 Implant Grade Steel Pin designed to be practical and easy to use. Fits all sizes of pins and bases in our threadless body jewelry line. Dimension: 4.5mm (L) x 4.5mm (W) x 1.2mm (THK); Pin Size: 0.45mm x 4.7mm.