These autoclavable desiccators are made of polypropylene (PP) 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 15 minutes. Non-vacuum (Plain) 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.