Earring hooks and jump rings are made of 925 copper, nickel free and hypoallergenic. Earring backs are clear silicone for comfort. This kit includes 150 fish hook earrings (75 pairs), 200 silicone earring backs, and 150 pieces of 4mm jump rings for Diy earring making. The lightweight hooks feature exquisite polishing with elegant curves and dynamic styles. Suitable for daily wear and special occasions. Use with your favorite accessories to create various gorgeous earring styles.