These autoclavable desiccators are made of polypropylene and polycarbonate and can hold vacuum up to 740mm Hg for 24 hours without any greasing. The PP stopcock has a self lubricating PTFE plug that works to create the vacuum, shut it off and release it. Autoclavable at 120°C for fifteen minutes. Non-vacuum desiccators are physically the same as vacuum desiccators; only difference is the absence of stopcock. Grease should be applied on the flanges to make it air-tight.