Temperature resistant from -60 °C up to 200 °C. Silicone liners with PTFE on both sides for less coring. Different hardness (durometers) to meet requirements of the various types of needles regarding penetration. Much cleaner than Natural Rubber, RedRubber or Butyl. The special, slitted liner for VWR (Merck®,)/Hitachi is only available unassembled, as the diameter with the most optimal valve effect does not achieve any pressfit in the cap. Enlargement of the diameter is only possible with negative effects on the building up of vacuums in the vial. Further Screw Seals 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: 5183-4442 / 100 - Waters: WAT094174 (alt.) - Chromacol: 8-SC-ST15 / 500 - National Scientific: C4013-60A / 100 C4013-65A / 100 (alt.) - Wheaton: 240602 - Finneran:- SUN/SRI International: 500 062 (alt.) 500 361 / 100 (alt.) - VWR: 548-0024 - Cronus Labhut: VCA-0804TB-100