HTS code 9902.08.96 covers "Fritted barium borosilicate glass with a mean particle size between 0.4 and 10 microns, Young's modulus of 71GPa, a density of 2.8 grams per cubic centimeter, radiopacity of 4.2, a refractive index of 1.53, and chemical composition of 55 percent silicon dioxide, 25 percent barium oxide, 10 percent boron trioxide and 10 percent aluminum oxide by weight (provided for in subheading 3207.40.10) " 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.