Dessicators are made of Polypropylene and Polycarbonate. These autoclavable vaccumdesiccators can hold vaccum up to 740 mm of Hg for 24 hrs. with out any greasing. Aninternal groove is provided on the flange to hold a silicon rubber O-ring. The Polypropylenestopcock is fitted with a self lubricating PTEF plug. This plug works three way i.e. vaccum creation, shutting off & vaccum releasing.