12-piece size adjustment ring set for Oura Ring 4. JZ98-53986 Sizing kit for rings. Sizes 4 to 15 Ships immediately via Mercari. Thank you. - Brand: Oura - Item Name: Sizing Kit for Oura Ring 4 - Contents: 12-piece size adjustment ring set - QR Code: With QR code - Country of Manufacture: China Thank you for viewing.