Amber glass precleaned vials have closed top polypropylene cap with teflon liner or open top polypropylene caps with teflon/silicone septa. Capacity: 40 ml. Catalog no. 184-900-10 has sodium thiosulphate (Na2S2O3) added. Vials with certificate have bar-coded boxes with the certificate number and a signed Certificate of Analysis listing analytes and detection levels. For volatile analysis.