Natural Rubber/TEF Seals Temperature resistant from -40°C up to 120°,C , Natural Rubber is ideal for multiple injections due to high resealability , but not as easy to penetrate than RedRubber/PTFE RedRubber/PTFE has a better purity than Natural Rubber/TEF , is softer and has less fragmentation, but doesn't offer the outstanding resealability as Natural Rubber/TEF Further Screw Seal , ND8 , with closed/open top resp. with white Caps are available upon request! This product is an alternative to the products (SKU) of these brands: Agilent:- Waters:- Chromacol: 8-SC-8RT1 / 500 - National Scientific: C4013-30A / 100 (alt.) - Wheaton:- Finneran:- SUN/SRI International: 500 068 / 100 (alt.) - VWR: 548-0Meer tonenMinder tonen