BLUEAIR GENUINE PRE-FILTER: For Blue Pure 211i Max air purifier. Blueair genuine pre-filter replacement in Fog Grey color is designed for optimal performance; Not compatible with 211+ and 211+ Auto LET’S CLEAR THE AIR SMARTER: Pre-filter is removable, washable, and designed for reuse; When the pre-filter requires a deeper clean, wash on a gentle, low-temperature cycle in the washing machine and hang to dry LET’S CLEAR THE AIR EASIER: Washable fabric traps pollen, pet dander and dust; Vacuum the exterior of the fabric pre-filter as often as you'd like LET’S CLEAR THE AIR FASTER: HEPASilent dual filtration technology delivers more clean air faster and uses less noise and energy than HEPA filtration alone LET’S CLEAR THE AIR WITH STYLE: Blueair is the only line of air purifiers with a customizable, washable fabric pre-filter in Scandinavian-inspired colors including Fog Grey, Limestone Beige, Moss Green and Sand Pink