Assembled screw cap with hole with PTFE/silicone septum black polypropylene hole cap, 8-425 thread, PTFE/silicone (red PTFE/creme silicone), septum thickness 1.5 mm, for use with 2 mL vial (standard opening), pkg of 1000 ea; find Supelco-854985 MSDS, related peer-reviewed papers, technical documents, similar products & more at Sigma-Aldrich.