HTS code 2520.20.00.00 covers "Gypsum; anhydrite; plasters (consisting of calcined gypsum or calcium sulfate) whether or not colored, with or without small quantities of accelerators or retarders › Plasters" 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.