Used in qualitative analytical techniques to determine and identify materials. It has excellent fine particle filtration (3¬µm) in the qualitative range. It is capable of retaining the fine precipitates encountered in chemical analysis. This filter paper is twice as fast as grade 5 with similar fine particle retention. It is often specified for boiler water analysis applications. It is an excellent clarifying filter for cloudy suspensions and for water and soil analysis. Retention: 3¬µm. 100 circles/box.