One complete filter change: One standard HEPASilent™ filter of polypropylene (traps particles).
Compatible with all Blueair 400 Series Air Purifiers (any model number that starts with 4).
These filters work with regular, E-Series, and Refurbished Blueair purifiers.
Product Dimensions: 20 x 3 3⁄4 x 9 7⁄8
Net Weight (including filters): 3 lbs.
Average Filter Life: 6 months.
Filter Efficiency: 99.97% of 0.1 micron particles on Speed One
Click here for the Blueair 400 Series SmokeStop Replacement Filters