Features & Specifications NeoAir Enviro PLUS SuperHEPA and OFS Filter Replacement Kit Use these replacement filters for the Neo-Air Enviro PLUS all in one Air Purifier system. This kit includes all necessary filters: 1 SuperHEPA and 1 OFS FilterThese filters will typically last around 1 year under normal use. The filter life depends on environmental factors, but your NeoAir Air Purifier will automatically tell you when the filters need replacement.