Grade GF/B Glass Microfiber Filter Binder Free, circle, 90 mm Grade GF/B is three times thicker than GF/A with higher wet strength and significantly increased loading capacity. Grade GF/B combines fine particle retention with good flow rate. Particularly useful where liquid clarification or solids quantification is required for heavily loaded fine particulate suspensions. Can be used as a finely retentive membrane prefilter. Used in LSC techniques where high loading capacity is required. Grade GF/B: 1.0 µm