Assembled screw cap with hole with PTFE/silicone septum black polypropylene hole cap, thread for 8-425, PTFE/silicone (red PTFE/white silicone), septum thickness 1.3 mm, for use with 2 mL vial (standard opening), pkg of 100 ea; find Supelco-SU860076 MSDS, related peer-reviewed papers, technical documents, similar products & more at Sigma-Aldrich