HTS code 9902.13.05 covers "Acrylic filament tow containing by weight 92 percent or more of polyacrylonitrile, not more than 0.01 percent of zinc and 2 percent or more but not over 8 percent of water, such tow dyed and presented in the form of bundles of crimped product each containing 315,000 to 360,000 filaments, with each filament of 3.3 decitex and with a length greater than 2 m (provided for in subheading 5501.30.00) " 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.