Actual inside diameter is marked on each ring
*Showroom Items: Limited Quantities. Excellent condition. Original protective wrapping or bag may be missing or open. Packaging, box and /or case (if applicable) is intact but may have slight markings No signs of wear on the item (used for display and/or demonstration purposes only). All gages come with Mitutoyo one year product warranty and will be professionally inspected and verified prior to shipment by our ISO 9001:2015 ACCREDITED SERVICE DEPARTMENT to meet or exceed the manufacturer’s specifications.