20 mL, GC/Headspace Aluminium Crimp Caps, Ultra Low Bleed PTFE/Silicone Septum. 100. VO2020CPS00. 20 mL, GC/Headspace Screw Vials, 20 ml, 22.50 x 75 mm (Dia. x Height), Flat Bottom. 100. SC2020M0000. 20 mL, GC/Headspace Screw Cap Magnetic Closure, Ultra Low Bleed PTFE/Silicone Septum. 100. CT2000AV000.