Grade B is a Binderless Borosilicate Glass Microfiber Filters. Fine porosity, medium to fast flow rate with a 0.9μm size particle retention, and a 1.85μm mean pore size. These binderless borosilicate glass microfiber filters are ideally suited for the collection of biochemical polymers that have been precipitated by denaturation. This material is twice as thick as Grade A with a higher loading capacity. May also be used as a particulate filter for gasses or as a prefilter.