Plain Desiccators are physically the same as Vacuum desiccators. The only difference is the absence of stopcock. Grease should be applied on the flanges to make it airtight. Both Vacuum and Plain Desiccators are provided with a thick perforated Polypropylene disc with a big hole in the centre for easy lifting. The tiny holes in the disc provide air troughs and support to the dishes. However, porcelain discs are advisable in case of incandescent crucibles.