before 12/31/2020 . 979. Fomblin T4 and Fomblin Z tetraol products Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.10.92 Ethene, 1,1,2,2-tetrafluoro-, oxidized, polymerized, reduced, methyl esters, reduced, 2,3-dihydroxypropyl ethers (CAS No. 925918–64–5) (provided for in subheading 3904.69.50) Free No change No change On or before 12/31/2020 . 980. Fomblin Z DOL and Fluorolink D series Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.10.93 Polyperfluoroethoxymethoxydifluoroethyl polyethylene glycol ether (CAS No. 88645–29–8) (provided for in subheading 3904.69.50) 2.2% No change No change On or before 12/31/2020 . 981. Fomblin Z DEAL, Fluorolink L series Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.10.94 Methoxycarbonyl-terminated perfluorinated polyoxymethylene-polyoxyethylene (CAS No. 107852–49–3) (provided for in subheading 3904.69.50) Free No change No change On or before 12/31/2020 . 982. Fomblin ETX, Fluorolink E series Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.10.95 Ethene, tetrafluoro, oxidized, polymerized, reduced, methyl esters, reduced, ethoxylated (CAS No. 162492–15–1) (provided for in subheading 3904.69.50) Free No change No change On or before 12/31/2020 . 983. Tetraethylene glycol Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.10.96 Mixtures of 95 percent perfluoropolyether polyethoxy alcohol (CAS No. 1260733–08–1) and 5 percent 2,2′-[oxybis(2,1-ethanediyloxy)]diethanol (Tetraethylene glycol) (CAS No. 112–60–7) (provided for in subheading 3904.69.50) Free No change No change On or before 12/31/2020 . 984. Fluorolink S10 Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.10.97 1-Propamine, 3-(triethoxysilyl)-, reaction products with Etesters of