Contents: Set of 5 earrings, Material: Surgical stainless steel Size: Gauge: 18G Shaft: 10mm Ball catch: 3mm Made of surgical stainless steel: Surgical stainless steel is a low-allergy stainless steel material used in medical devices such as surgical instruments. It is resistant to corrosion, oxidation, and heat, and is rust-resistant. Therefore, it is also recommended for continuous wear. (※However, this does not guarantee that metal allergies will not occur.) I accidentally purchased the wrong size. If anyone is interested in them, I would like to give them away.