4 filters per pack. Carbon filters capture larger particles and help reduce unpleasant odors. Carbon absorbs odors generated by pets, mildew, cooking, construction materials, and more. Filter size: 9-1/4" L. x 6" W. Fits Holmes Model No. HAP615, HAP625, HAP650, HAP675, HAP675RC, HAP715, HAAP725, HAP750, HAP1625, HAP1650, HAP1715, HAP1725, HAP8650, HAAP1750, and GE Model No. 106633, 106643, and 106653.