N 20 bimetal crimp cap, blue/silver, center hole Silicone blue transparent/centrical PTFE-lamination colorless Hardness: 45° shore A Thickness: 3 mm pack of 100

Bi-metal crimp closures support transportation of the vial via magnet, as for e.g. in the CTC Combi PAL, the Shimadzu AOC 5000/6000 or the Gerstel autosampler. They are generally more difficult to crimp/decap which is why Headspace screw neck vials N 18 may be a more convenient alternative. We recommend Silicone/PTFE septa as the optimal choice for Headspace, as they offer a temperature resistance form -60 °C up to 200 °C, highest analytical purity and excellent penetration properties. These closures with a molded, high purity Silicone/PTFE septa are only laminated with PTFE in the contact area with the sample. Thus the elastomeric Silicone can achieve on the vial's glass rims a very tight seal, while in comparison a completely PTFE covered septum would have a very slippery surface on the glass and could easily be twisted around. Septa are assembled, caps are ready-to-use. Septa are shown for illustration purposes only, images upside down.