; bis[[dimethyl (trimethylsilyloxy)silyl]oxy]-dimethylsilane (CAS No. 141–63–9) (provided for in subheading 2931.90.90) Free No change No change On or before 12/31/2024 . 4328. Vinyltrimethoxysilane Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.21.33 Ethenyl(trimethoxy)silane (CAS No. 2768–02–7) (provided for in subheading 2931.90.90) Free No change No change On or before 12/31/2024 . 4329. n-Octyltriethoxysilane Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.21.34 Triethoxy(octyl)silane (CAS No. 2943–75–1) (provided for in subheading 2931.90.90) Free No change No change On or before 12/31/2024 . 4330. Dimethylbis(s-butylamino)silane Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.21.35 N-[(Butan-2-ylamino)-dimethylsilyl]butan-2-amine (CAS No. 93777–98–1) (provided for in subheading 2931.90.90) Free No change No change On or before 12/31/2024 . 4331. Aqueous solution of potassium methyl siliconate Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.21.36 Tripotassium