Thermo Scientific 13mm Autosampler Vial Septa Red PTFE/White 13 04 2022 For use with 13-425 threaded caps or 13mm Snap/Crimp Caps, Thermo Scientific™ 13mm Septa are available in PTFE/ Red Rubber, PTFE/Silicone or Red PTFE/White Silicone/Red PTFE to suit a variety of applications.