Aijiren Headspace Vials and Closures – Chrom Tech, Inc. Aijiren Headspace Vials & Closures Aijiren 10 mL and 20 mL certified screw and crimp style, clear or amber glass headspace vials and associated 11 mm, 18 mm, and 20 mm headspace caps are engineered to prevent sample contamination while providing consistent, secure seals.