No. 400R Filtration speed Medium, Retention Crystalline retains medium particles ( 5 to 10 µm) such as CaCo3 , PbSo4 , CaCo4, MnCo3 , ZnS, AgCl
No. 410R Filtration Speed Fast, Retention - coarse and gelatinous precipitates retention particles >15 µm, filters hydroxides and metallic aerosols, used in environmental monitoring, determining silica content in steel
No. 420R Filtration Speed - Slow Retention-crystalline, particle retention upto 2.5 µm, alpha cellulose content >98%, used in typical analytical preciprates include SrSo4 , BaSo4 , HgCrCo4 and colloidal dispersion, gravimetric analysis