Autosampler Vials, Caps and Closures | Aijiren Tech Scientific Autosampler Vials, Caps and Closures Aijiren Tech™ 20 mm Headspace Vials, Septum, and Caps Headspace vials are available in clear or amber glass with a round or flat base, a crimp seal with a beveled or square edge finish, or with a screw-thread finish.