12/31/2020 . 974. Fomblin W 500 Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.10.87 Mixture of poly(1-[difluoro(trifluoromethoxy)methoxy]-1,1,2,2-tetrafluoro-2-(trifluor omethoxy)ethane) (CAS No. 69991–61–3) and perfluoropolymethylisopropyl ether (CAS No. 69991–67–9) (provided for in subheading 3904.69.50) Free No change No change On or before 12/31/2020 . 975. Fomlbin M and Z lubricants Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.10.88 1,1,2,2 Tetrafluoroethene, oxidized, polymerized (CAS No. 69991–61–3) (provided for in subheading 3904.69.50) 2.5% No change No change On or before 12/31/2020 . 976. Fomblin MD grades Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.10.89 Ethene, 1,1,2,2-tetrafluoro-, oxidized, polymerized, reduced, ethyl esters, reduced, N-[2-[(2-methyl-1-oxo-2-propen-1-yl) oxy] ethyl] carbamates (CAS No. 1385773–87–4) (provided for in subheading 3904.69.50) Free No change No change On or before 12/31/2020 . 977. Fomblin DA306 Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.10.90 1-Propene, 1,1,2,3,3,3-Hexafluoro-, oxidzed, polymd., reduced, hydrolized reaction products with ammonia (CAS No. 370097–12–4) (provided for in subheading 3904.69.50) Free No change No change On or before 12/31/2020 . 978. Fomblin DA 305, Galden MF310 Subchapter II of chapter 99 is amended by inserting in numerical sequence the following new heading: 9902.10.91 1-Propene, 1,1,2,3,3,3-hexafluoro-, oxidized, polymerized, reduced, hydrolyzed (CAS No. 161075–14–5) (provided for in subheading 3904.69.50) Free No change No change On or 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,