Sartorius, 16537-----K, Minisart 0.45um, 1.1" High Flow Syringe Filter, Polyethersulfone, Sterile, Luer Lock Outlet. Minisart High Flow with polyethersulfone (PES) is optimal for highest flow rates and a pH of 3 - 12. Type 16537 with a pore size of 0.45 µm can be used for clarification and has a male luer lock outlet.