Cytiva - Whatman 1004-150 Qualitative Filter Paper Standard Grade Qualitative Filter Paper Standard Grade, Circle, Diameter: 150mm, grade 4, AirFlow rate:3.7 s/100 ml/in2, Ash Content: 0.06% Basis Weight:96 g/m2, Flow rate:Very fast, Particle retention:25 um, Tensile Strength: 28.4 N/15 mm, Thickness:205 um (typical) Exact Match 28460-120