For Larger Volume Samples or Samples with Heavy Particulate Concentrations. The 90mm Filter Surface Provides a More Efficient Filtration Up to Four Times Faster and Has Less Chance of Clogging Than the 47mm Filters. The Frits are Removable and Are Available in Glass or PTFE. Used for General Filtration. The Fritted Glass Support Disc Can Be Replaced If It Becomes Clogged or Exchanged if Sample to Sample Cross Contamination Is a Concern. This Unit is Supplied with a Coarse Glass Frit for Filter Support, Glass Support Base, 1 Liter Graduated Funnel, Anodized Aluminum Clamp and a #8 Stopper.