HTS code 9105.99.40 covers "Other clocks › Other › Standard marine chronometers having spring-detent escapements › Not constructed or designed to operate for over 47 hours without rewinding › Having over one jewel" 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.