Caps, Headspace, Screw Top, with White Silicone Rubber / Red PTFE Pre-Slit (Star Shape) Septa, fitted in Steel, Magnetic, Silver Caps with 8mm center holes. For use with 18mm Precision Thread Headspace Vials. MicroSolv Brand. 100/PK.
Star Shape Pre-Slit provides a greater target area for needles and are easier to penetrate but may not reseal as well as single or non-slit septa. Recommended for SPME autosamplers including CTC Combi Pal®.
Silicone Rubber / UltraClean PTFE Septa is 55⁰ Shore A (hardness) and is 1.5mm thick. Cap has ND18 Screw Threads.