From Pierced Nations Body Sensitive line of jewelry! NWT, never worn or taken out of packaging 16g, 5/16” Perfect for a rook, daith, anti-tragus, or eyebrow piercing ASTM F-136 TITANIUM*** Internally threaded Genuine Cubic Zirconia, with replacement silver balls ***What is ASTM F-136 Titanium?*** This line of high grade titanium is hypoallergenic and is featured in our Body Sensitive Line. ASTM F-136 Titanium is sold at a higher price point because it is internally threaded, features Swarovski gems & semiprecious stones, and the entire piece of jewelry is comprised of ASTM F-136 Titanium (including decorative features). This is the best option for those with nickel allergies or sensitive skin. • Internally threaded: the thread or "screw" is on the removable end, such as the ball on the end of a barbell. • Hypoallergenic means that it doesn't contain irritants or materials that are known to potentially cause allergic reactions.