Sartorius Minisart™ SRP Syringe Filters are single-use filtration units with a chemically resistant PTFE membrane and male luer slip outlet. Available in 4, 15 and 25mm diameter filters with 0.2 or 0.45 μm pores. Pricing and Availability. Thermo Scientific™ Titan3™ PTFE (Hydrophobic) Syringe Filters.