2 & 4 Packs - Brand New  3-in-1 premium quality materials replacement filters. Filter captures up to particles as small as 0.3 microns such as smoke, dust, and so on. It is a great, affordable option for your home and create a comfortable home environment. The filter should be replaced approximately about 3 months.   This filter measures 9.5 in * 6.7 in * 1.5 in" The more you buy the more you save.  Free shipping within the USA only.  Any questions please ask prior to purchasing.