14Kt Yellow Gold Threadless Cat Top is made of solid 14kt nickel-free Yellow 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. Top Size: 4mm (L) x 6mm (W) x 0.9mm (H); Pin Gauge: 25g