Vial crimp seals, BiMetal (magnetic), 20 mm, with PTFE/silicone septa, pkg 100 red seal, septa (blue PTFE/white silicone), diam. × thickness 20 mm × 3 mm; find Supelco-29171-U MSDS, related peer-reviewed papers, technical documents, similar products & more at Sigma-Aldrich.