Advantec Unlaminated PTFE Hydrophilic Membranes PTFE Unlaminated Membrane Filters, Hydrophilic, 0.2 Micron, 90mm, 25/Pk (H020A090C) Durable, efficient, and broadly compatible, these pure, hydrophilic PTFE membranes are ideal for use with HPLC seperations, aqueous/organic solvents, and many of your other filtration needs. Pack of 25.