Headspace Vials found in: Headspace Vials, Standard 22 x 38 Crimp Top, Headspace Vials, Screw Thread, Metal Threaded Closure (18mm), Headspace Vials, Seals.. Clear glass vials with 20mm crimp seal finish are designed to fit most headspace autosamplers Flat bottom vials maximize heating efficiency when used with bottom Round bottom vials are more easily handled by robotic arms that lift