This Reeve Angel qualitative filter paper, Grade 230, is manufactured primarily for routine, noncritical laboratory filtration applications. It contains wet-strength additives and should not be used for Kjeldahl Nitrogen determinations. These Reeve Angel papers provide consistent quality and performance. For fine chemicals, pharmacology, oils, culture media, emulsions, soaps and detergents, water tests. Diameter: 15cm. Thickness: 0.40mm. Surface: Crepe. Shape: Circle. Precipitates Retained: Coarse/Gelatinous. Filtration Speed: Very Fast. Nominal Retention 98% Efficient At: 25 to 30μm. Weight: 123g/m².