HTS code 9902.16.04 covers "Ring gears, with diameter 30 cm or more but not over 200 cm and height of 6 cm or more but not over 30 cm, the foregoing to be assembled onto the periphery of a flexplate or flywheel for a diesel engine ranging in cylinder capacity equal to or greater than 5,000 cc but not exceeding 95,000 cc (provided for in subheading 8483.90.50)" under the US Harmonized Tariff Schedule. This is the official duty rate charged by US Customs when this product is imported into the United States, sourced directly from the U.S. International Trade Commission and refreshed daily.