This is a set of necklaces and earrings that are compatible with metal allergies. I have only tried them on, so I don't know if there will be an allergic reaction, but I purchased them as metal allergy-friendly products at a shop I often use. (Size: measured by an amateur) Necklace: Maximum 48 cm Earrings: 3.2 cm in diameter The material is believed to be surgical stainless steel (I'm sorry, I forgot). There are no signs of deterioration, but there may be oversights, so please understand that these are used items.