HTS code 9902.13.52 covers "Socks of synthetic fibers, with uppers of neoprene measuring 3.5 mm in thickness and covered on both surfaces with knitted jersey fabric of nylon; each such sock having an integrated fold-down cuff of knitted jersey fabric of nylon, each cuff with a molded hook to allow connection to wading boot and designed to prevent debris and gravel from getting inside wading boot, such socks anatomically formed (provided for in subheading 6115.96.90)" 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.