The transport swab stick comes in plastic , aluminum and flexible twisted aluminum. The swab plastic stick with polyester tip in polypropylene test tube diam. 12x150 mm with liquid transport medium for Virus, sterile (26091). The swab aluminium stick with polyester tip in polypropylene test tube diam. 12x150 mm with liquid transport medium for Virus, sterile (26092). The swab flexible twisted aluminium stick with polyester tip in polypropylene test tube diam. 12x150 mm with liquid transport medium for Virus, sterile (26093). Perfect for collecting specimens may it be for study or evidence. Most authorities prefer this for DNA sampling .