Experience cleaner, fresher air with our True HEPA Room Air Purifier Filter, designed to capture 99.97% of airborne particles as small as 0.3 microns. This 2-pack filter, measuring 9.96 inches in length, 4.69 inches in width, and 1 inch in thickness, is compatible with Filtrete FAP-TT-ADH devices and select Holmes and Honeywell air purifiers. Replace every 6 months for optimal performance.