Frontier Replacement Filter. Hi-Flow virus filter provides ultimate protection from virus, bacteria, Cryptosporidium and Giardia with up to 500 ml/minute flow rate. Designed for use with the Frontier Max Filtration System (67018). Reusable filter tube protects the filter during storage and transport and can be repurposed to hold small items. Miraguard Antimicrobial technology suppresses the growth of bacteria, algae, fungus, mold, and mildew within the filter media. Filters 120 gallons. Hang packaged.