Thomson SINGLE StEP Standard Filter Vials - Restek. Minimize sample loss by eliminating multiple transfers. Color-coded caps allow easy identification of 0.2 μm or 0.45 μm membranes in PVDF, PTFE, PES, or nylon. iPure PTFE Membrane Syringe Filter, 25mm, 0.22μm, 100-pk. Product Size, Pack of 100. For Use With, HPLC, SPE. Type, Syringe Filter.