This final rule amends the U.S. Customs and Border Protection (CBP) Regulations to reflect an extension and amendment of import restrictions on certain archaeological and ecclesiastical ethnological material of the Hellenic Republic (Greece). The restrictions, which were originally imposed by CBP Dec. 11-25 and last extended in CBP Dec. 16-21, are due to expire on November 21, 2021. The Acting Assistant Secretary for Educational and Cultural Affairs, United States Department of State, has made the requisite determinations for extending the import restrictions that previously existed, and the Government of the United States and the Government of Greece entered into a new agreement to reflect the extension of these import restrictions. The new agreement, which enters into force on November 21, 2021, supersedes the existing Memorandum of Understanding (MOU) that became effective on November 21, 2016, and enabled the promulgation of the existing import restrictions. Accordingly, the import restrictions will remain in effect for an additional five years, and the CBP regulations are being amended to reflect this extension until November 21, 2026. To fulfill the terms of the new MOU, the Designated List of cultural property, which was described in CBP Dec. 11-25, is amended in this document to correct certain typographical errors, to add certain coins from the Byzantine and Medieval periods, to clarify pottery styles, and to include post-Byzantine ethnological material dating up to A.D. 1830.