20 mm Magnetic Cap/Septa 8 mm Hole w/1.3 mm thickness 100 N6356564 Silicone/PTFE Trans Blue (SPME liner) 20 mm Magnetic Bi-Metal Cap/Septa w/3.0 mm 8 mm thickness 100 N6356565 PTFE/Blue Liner 20 mm Bi-Metal Cap/Septa w/3.0 mm Silicone 8 mm thickness 100 N6356566 PTFE Transparent Blue Liner Specialty Headspace Caps and Septa