0.2 Micron, 293mm, PTFE Unlaminated Membrane Filters. 10/Pk. PTFE Unlaminated. $628.92. + -. Add to Cart. Showing 1 to 6 of 6 entries. Our unsupported, hydrophobic, PTFE membrane filters are ideal for sterilization and venting applications involving air, gasses, and solvents/acids incompatible with most other filters.