; (B) by striking Free and inserting 3.9% ; and (C) by striking 12/31/2020 and inserting 12/31/2024 . (15) AE 747 ether Heading 9902.05.07 is amended— (A) by amending the article description to read as follows: 2-Chloro-4-(methylsulfonyl)-3-((2,2,2-trifluoroethoxy)methyl) benzoic acid (CAS No. 120100–77–8) (provided for in subheading 2930.90.29) ; (B) by striking 5.7% and inserting 6% ; and (C) by striking 12/31/2020 and inserting 12/31/2024 . (16) Thiodicarb Heading 9902.05.15 is amended— (A) by amending the article description to read as follows: Methyl (1E)-N-[methyl-[methyl-[(E)-1-methyl- sulfanylethylideneamino] oxycarbonylamino] sulfanyl- carbamoyl]oxyethanimidothioate (Thiodicarb) (CAS No. 59669–26–0) (provided for in subheading 2930.90.43) ; (B) by striking Free and inserting 3.6% ; and (C) by striking 12/31/2020 and inserting 12/31/2024 . (17) Glufosinate-ammonium Heading 9902.05.37 is amended— (A) by amending the article description to read as follows: 2-amino-4-[hydroxy(methyl)phosphoryl]butanoic acid;azane (Glufosinate Ammonium) (CAS No. 77182–82–2) (provided for in subheading 2931.39.00) ; (B) by striking 1.5% and inserting 3.5% ; and (C) by striking 12/31/2020 and inserting 12/31/2024 . (18) Pyraflufen-ethyl Heading 9902.05.63 is amended— (A) by amending the article description to read as follows: Ethyl 2-chloro-5-(4-chloro-5-difluoromethoxy-1-methyl-1H-pyra- zol-3-yl)-4-fluorophenoxyacetate (Pyraflufen-ethyl) (CAS. No 129630–19–9) (provided for in subheading 2933.19.23) ; (B) by striking Free and inserting 2.2% ; and (C) by striking 12/31/2020 and inserting 12/31/2024 . (19) Fipronil Heading 9902.05.66 is amended— (A) by amending the article description to read as follows: (RS)-5-Amino-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-(trifluoromethysulfinyl)-1H-pyrazole-3-carbonitrile (Fipronil) (CAS No. 120068–37–3) (provided for in subheading 2933.19.23) ; (B) by striking 4.4% and inserting 5.4%