Sterile, 250 mL Steritop Quick Release-GP 45 mm threaded bottle top filter with 0.22 µm pore size fast flow polyethersulfone (PES) Express PLUS membrane. View Products on Sigmaaldrich.com. S2GPT02RE. 12 pack, GP, 0.22 µm, polyethersulfone, 250 mL 45 mm, radio-sterilized. Price could not be retrieved.