Closure Color: Red/Silver: Description: Magnetic, PTFE/Blue Silicone Septa, 3 mm thick, 8 mm hole: Color: Red, Silver, Blue: Material: Silicone: Septum: PTFE/Blue Silicone: Closure Material: Aluminum/Tin Plate: Closure Type: Crimp (Magnetic) Thickness (Metric) 3 mm: Closure Size: 20 mm: For Use With (Equipment) 20 mm Headspace Vials: Unit Size: Each