The Blomdahl Medical Plastic Rainbow Earring is a 4mm single stud earring featuring an iridescent rainbow crystal set in medical-grade plastic. This hypoallergenic earring is designed for sensitive ears and newly pierced lobes. As this is a medical/hygienic personal care product, specific usage and care instructions should be followed according to the manufacturer's guidelines. Please consult with a healthcare professional or piercing specialist for proper use.