Magnetic Screw Cap, 18 mm, Silver Steel, with Blue PTFE/White Silicone Microcenter SPME Septa, Minimum Order Quantity of 10 Packages

Microcenter lined caps have a standard silicone thickness around the perimeter of the liner to maintain good fit, but with a thin 0.060 in center liner to allow penetration from the SPME injection needle without damage to the fibers.