Vial 9mm Borosilicate Glass Screw Thread Autosampler Vials with White Marking Patch, Clear Screw Caps 9mm Polypropylene Screw Caps PTFE / Silicone Septa: 0.005" Red PTFE and 0.035" White Silicone, 0.040" total thickness, suitable for gas chromatography Cleanroom Clean MicroLiter vials are cleaned and assembled in a Class 10,000 clean room to