H2O Survival Water Filter Travel Straw MAX. Upgraded High Capacity Water Purifier that can filter up to 530 Gallons for Bacteria, Heavy Metals & Viruses via an Exclusive Hi-Density Filter System utilizing 0.01 micron Membrane/GAC and MIR Poly-Iodine Technology.>Smaller 0.01 Micron Pores=Better Filtration.