This Whatman™ 30 x 100mm high-purity glass microfiber thimble is manufactured from 100% pure borosilicate glass. It is used for specialized applications. The thimble is completely free of binders or additives and can be used at temperatures up to 500°C or when using solvents that are incompatible with cellulose thimbles. This thimble is also used in pollution monitoring techniques (0.8µm nominal particle retention). Typical thickness is 1.7 mm. Dimensions: 30 x 100mm. 25/Pack. Whatman™ #: 2814-300.