. 4121. Silica gel cat litter Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.19.21 Cat litter formulated from synthetic silica gel, put up for retail sale (provided for in subheading 2811.22.10) Free No change No change On or before 12/31/2024 . 4122. Sulfuryl dichloride Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.19.22 Sulfuryl dichloride (CAS No. 7791–25–5) (provided for in subheading 2812.19.00) Free No change No change On or before 12/31/2024 . 4123. FS-10D acicular electroconductive tin oxide Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.19.23 Dispersions of tin(IV) oxide (CAS No. 18282–10–5), doped with antimony pentoxide (CAS No. 1314–60–9), in water (provided for in subheading 2825.90.20) Free No change No change On or before 12/31/2024 . 4124. Certain potassium fluoride Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.19.24 Potassium fluoride (CAS No. 7789–23–3), spray-dried, crystalline, granular or any dry form (provided for in subheading 2826.19.90) Free No change No change On or before 12/31/2024 . 4125. Other potassium fluoride Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.19.25 Potassium fluoride (CAS No. 7789–23–3) other than spray-dried, crystalline, granular or any dry form (provided for in subheading 2826.19.90) Free No change No change On or before 12/31/2024 . 4126. LiPF6 Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.19.26 Lithium hexafluorophosphate (LiPF6) (CAS No. 21324–40–3) (provided for in subheading 2826.90.90) 1.9% No change No change On or before 12/31/2024 . 4127. LiPO2F2 Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.19.27 Lithium difluorophosphate (LiPO2F2) (CAS No.