Some brown rust can be seen in places. [Wire Diameter] Approximately 0.8mm [Size] Size 12, Inner Diameter: Approximately 16.5mm, Inner Circumference: Approximately 52mm [Color] Yellow Gold Gold-filled, safe for those with metal allergies Gold-filled is made by pressure-bonding 14-karat gold to a base metal (brass). If the gold weight is more than 1/20th of the total weight, it is called gold-filled. It has a complete 14-karat gold surface due to the 14-karat gold being pressure-bonded, but the core is brass (which doesn't touch the skin), making it affordable. Therefore, the appearance is similar to gold parts, and it differs from the appearance of plated parts. It is also more durable (less likely to peel) than plating. ◆Material 14kgf, stamped