The Whatman grade 603g standard glass fiber thimble is made from borosilicate glass fibers with inorganic binder. Has excellent mechanical strength and retention. This standard single thickness thimble has a wall thickness of approximately 1mm and 10.0µm nominal particle retention. The high purity of the materials ensures reliable and reproducible analytical results. 26.8 x 68mm. Thickness: 1.5mm. 25/Pack. Whatman #: 10371114.