These heart-shaped earrings (thread through) are made from Medical Plastic. These earrings are so comfortable my daughter loves them and she can put them on herself (she is 8 years of age). These earrings look amazing, feel great and are low allergy risk for people with sensitive skin. I do also like the quick turnaround time for postage and delivery, also the way in which it is packaged giving us another option for gifting.