Measures 22x23.5x2 (Actual Size). Efficiency designed to meet the air filtration efficiency criteria required to gain points toward certification in the Leadership in Energy and Environmental Design (LEEDs) Green Building rating system. Electrostatically charged filter media captures airborne allergens smaller than 1 micron! Great for helping reduce airborne allergens such as bacteria, particles that carry viruses, pollen, mold spores, fine dust, and pet dander. Accumulairtrade; filter material will not support the development of mold, mildew, bacteria or other microorganisms in normal use. No chemicals added. Accumulairtrade; filters are chemical free! Over 30-times more efficient at capturing micro particles than ordinary fiberglass filters. Lasts UP TO 3 months!