Polylab Desicators are made of Polypropylene and Polycarbonte. These autoclavable vaccum desicators can hold vaccum upto 740mm of Hg for 24 hrs. without any greasing, the top dome, moulded in rigit and transparent polycarbonate, gives a crystal clear view of the deisccnt placed inside. The knurled knob on the top provides easy handling of the dome. The lower part is made of Polypropylene. An internal groove is provided on the flange to hold a silicon rubber O-Ring. The Polypropylenestopcock is fittedwith a self lubricating PTFE plug.This plug works three way i.e. vaccum creation,shutting off & vaccum releasing.