Caps Perkin-Elmer Autosampler Vials, 12 x 30 mm, 8/425 Product # Description. Add to Cart. 27261-UAsseled screw cap with hole with PTFE/silicone septum 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 100 ea