Skip steel swarovski gem ball top - internally threaded images slider SKU: Steel Swarovski Gem Ball Top - Internally Threaded Sign-up to see price These 14g–12g Swarovski gem balls are made of stainless steel and come in your choice of gem colors and sizes, ranging from 2mm to 4mm. Product Details: Material: 316L ASTM F-138 Implant Grade Stainless Steel Threading: Internal 1.2mm; 2mm post Gem size options: 2mm–4mm