Over 30-times more efficient at capturing micro particles than ordinary fiberglass filters. The all new Accumulair Diamond with its MERV 13 rating is the highest efficiency Accumulair filter on the market! Great for helping reduce airborne allergens such as bacteria, particles that carry viruses, pollen, mold spores, fine dust, and pet dander. Accumulair filter material will not support the development of mold, mildew, bacteria or other microorganisms in normal use.