Thermo Scientific™ 11 mm Autosampler Vial Crimp Caps. Minimize contamination from handling with pre-assembled caps and septa; compatible with most HPLC and GC autosamplers. Pricing & Availability. Specifications. Closure Size. 11 mm. 4. Thermo Scientific™ 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.