Vacuum Desiccators Transparent are made of polycarbonate. These autoclavable vacuum desiccators can hold vacuum up to 740 mm of Hg for 24 hrs without any greasing. The top dome and bottom base, moulded in rigid and transparent polycarbonate, gives a crystal clear view of the desiccant placed inside. The knurled knob on the top provides easy handling of the dome. An internal groove is provided on the flange to hold a silicon rubber O-Ring. The polycarbonate desiccator is fitted with a self-lubricating PTFE plug. This plug works three-way i.e. vacuum creation, shutting off & vacuum releasing.