SDS. Pricing. 27020. black polypropylene hole cap, thread for 18-400, PTFE/silicone, septum thickness 1.5 mm, for use with 15 mL vial, pkg of 100 ea. Expand. Hide. 27261-U. black polypropylene hole cap, thread for 8-425, PTFE/silicone, Top Hat (septa and closure designed to fit together tightly), for use with 2 mL vial, 4.6 mm opening, pkg of