Blueair SmokeStop Filter for 501 and 601

The optional SmokeStop filter kit provides your Blueair system with better protection from smoke and other airborne gases. This complete SmokeStop filter change kit fits all Blueair 500/600 Series (501, 601) and comes complete with: 3 enhanced HEPASilent filters of polypropylene (equal particle efficiency), with more activated carbon for better smoke and gas removal. Replace every 6 months.