ITEM NAME:1/2 oz. 14 grams Pyrex Glass Wool, Filtering Fiber Quartz wool Quartz fiber 16#.Commonly used in chromatography columns, this fine filtering fiber is made of Pyrex borosilicate glass. (14 grams) of Pyrex glass wool. Quartz wool. Strand breaking strength. Fine, soft cotton. The following 12, temperature 1700 degrees.