VWR® 20 mm Crimp Seal Headspace Vials. Vials Chromatography Vials. Clear 20 ml headspace vials designed to fit most headspace autosamplers. Round bottom vials fit PerkinElmer®, Tekmar®, and Varian® headspace autosamplers. Flat bottom vials fit Aijiren® and Carlo Erba autosamplers. Ordering information: 20 mm crimp seals have to be ordered