Laboratory 20Ml Headspace Vial Sigma-Aldrich-Aijiren Headspace vials and closures must form a tight seal for accurate analysis with reproducible results. 20 Mm Vial at Thomas Scientific 20 Mm Vial found in: 22 mL, 20 mm, Headspace Screw Top Vial with P logo, 20 mL, 20 mm, Crimp Top Vial with Write-on Patch and Fill Lines, Headspace Crimp..