Septa, tan PTFE/silicone white tan PTFE/silicone, diam. × total thickness × PTFE thickness 18 mm × 0.060 in. × 5 mil, for use with 22 mL vial, pkg of 100 ea; find Supelco-27177 MSDS, related peer-reviewed papers, technical documents, similar products & more at Sigma-Aldrich