Zia Amethyst Attachment (Barbell not included) 18Kt Yellow Gold Measuring 7.5 x 7.5 mm Internally Threaded for 18G/16G ( 1 mm/ 1.2 mm) Non-Sterile Vendor: Anatometal Fits Anatometal barbells in 18G/16G and fits internally threaded barbells in 18G/16G from all APP approved jewellery vendors (USA)