Although the item has been opened, it is unused. arena Swimming Cap Model Number: ARN-6406 There is no size notation on the cap itself, but according to the manufacturer, it is sold as **Free Size (ONE SIZE)**. It is made of silicone and is elastic. If you are concerned about the size, please consider it to be equivalent to a general adult free size. *There are individual differences in how the size feels. Please consider purchasing only if you understand that this item has been stored at home. --- A high-quality polyester swimming cap in black. - Brand: arena - Model Number: ARN-6406 - Color: Black Thank you for viewing.