Headspace GC Vial 20 ml with Aluminium Crimp Cap. Manufacturer of Chromatography Vials - Headspace GC Vial 20 ml with Aluminium Crimp Cap, GC Vials Magnetic Crimp Cap, GC Headspace Vials Screw Cap and HPLC Headspace Vial 20mm-Headspace Vial 20mm-Autosampler Vials . Available in flat or rounded bottom designs for accurate instrument compatibility.