... mm8) Length: 10", 20", 30", 40"9)Applicable PH value:1-1310)10)Precision of filtering(micron):1,3,5,10,20 ... ,30,40,50at last, there is a largest feature that our filter cartridge has ... inside laryer is tight,which could filter more thing. the outside laryer is loose, which could make water flowing qucikly. micron filter cartridges