Aijiren Aluminum Crimp Seal with PTFE/Silicone Septa for Headspace Vial, Aluminium Cap, plain, 10mm centre hole; They are offered in packs of 100 20 mm Headspace Vials, Septum, and Caps - Aijiren Tech Scientific. Description. 20mm Composite Magnetic Crimp Cap, 8mm hole. Diameter (Metric) Inner. 20 mm. Material. Aluminum. Color. Blue. Price (USD). Price: 20.00. Headspace Cap for 20mm Vial Closure, Aluminium Silicon / Teflon . Headspace Crimp Cap for 20mm Vial Closure, Aluminium with ...