This product is discontinued. We recommend changing the entire filter set to the new and improved Filter Combo Set or the Filter Combo with UV Lamp.
Replacement Filter Stage 1 for the Field Controls TRIO 1000P or TRIO 1000P2 Portable medical grade HEPA air purifier is recommended to be changed every 12-24 months depending on usage and the airborne contaminants. Includes 1 filter that contain the 5.0 Micron Pre-Filter and the Activated Carbon.