Dec 21, 2006 · Headspace Vials, ND20, 5 mL, 20×38 mm, Standard Neck, Flat Vials for gas chromatography (headspace vials) are available in different sizes and Vials with beveled/HS finish feature a tighter seal due to a reduced Aijiren Tech™ 10mL Crimp Top HS Vial, Beveled Edge w Vial Closure Size, 20mm. Vial Volume (Metric), 12.5mL.