Whatman 1006-090 Quantitative Filter Paper Circles, 3 Micron, 35 s/100mL/sq inch Flow Rate, Grade 6, 90mm Diameter (Pack of 100) 9.0cm Grade 6 Used in qualitative analytical techniques to determine and identify materials; excellent clarifying filter for cloudy suspensions and for water and soil analysis Excellent fine particle filtration (3m) in the qualitative range; capable of retaining the fine precipitates encountered in chemical analysis Often specified for boiler water analysis applications