Crimp Sealing Chromatography Vial Flat Bottom WHEATON Headspace Vials, ND20, 10 mL, 22x46 mm, Long Neck, Flat Increased wall thickness (1.2 mm) compared to standard chromatography vials (0.9 mm) Vials with beveled/HS finish feature a tighter seal due to a reduced sealing surface between crimp and glass; Rounded bottom vials are ideal for