Fluoropolymer NMR Tube Caps • 4mm • 50 Pack SKU TC-4-PTFE-50PK $270.51 Available to Order Quantity -+ Add to Cart Details Redesigned Fluoropolymer NMR Tube Caps 4 mm50 PackBlueRedesigned tapered fluoropolymer closure system that works together with our fire-polished tube ... Details Back DetailsRedesigned Fluoropolymer NMR Tube Caps4 mm50 PackBlueRedesigned tapered fluoropolymer closure system that works together with our fire-polished tube ends, offering superior sealing and sample integrity, preventing sample loss even during temperature gradients.