Septa for 8-425 Screw-Thread Vial Caps, Thermo Scientific. Descripción: Coring-resistant, 8mm septum is made of pure white silicone laminated to 5mil red PTFE. For multiple injection applications. Fits open-top polypropylene screw caps (see 66030-412), for use with 2mL glass autosampler vials (see 66001-236,