This item: Deschem 47mm,Hydrophobic PTFE Membrane Filter,Made by Polytetrafluoroethylene,50 Sheet/Pack. $18.99. In Stock. Ships from and sold by Deschem. EISCO CH0688 Labs Clamp Retort, 3 PVC Coated Prongs (opens to 90mm in dia.) with Boss Head. $9.99. In Stock.