... 25mm,47mm, 60mm,90mm,120mm,293mm ... About hydrophilic lab membrane filter discs:Specification:Material:Removal Rating :0.20µm, 0.45 ... CompatibilityStable among pH3-14,Resist against most organic solvent and alkaline liquid;Flow Rate(Water)p100 kPa0.2µm23ml/min/cm20 ... usually apply CN-CA membrane,which is more suitable. membrane filter discs