HTS code 9902.12.88 covers "Synthetic filament yarn (other than sewing thread) not put up for retail sale, single, with a twist exceeding 50 turns/m, of nylon or other polyamides, measuring 23 or more but not over 840 decitex, each formed from 4 to 68 filaments and containing 10 percent or more by weight of nylon 12 (provided for in subheading 5402.51.00)" 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.