Shimadzu Scientific US Webstore - Vials, 20mL Package of 20mL clear headspace round bottom vials with 20mm aluminum crimp caps (silver in color) and Silicone/PTFE Septa. Cap: Aluminum 20mm Crimp Cap. Septa: Silicone (White)/PTFE (Beige), 45° shore A, 3.2mm, Vial Deminsions: 20mL, 75.5 x 22.5mm round bottom, Package Size: 100/pk Nonmagnetic cap.