Replacement OEM air filter from Stihl. Keep your chainsaw running efficiently with a clean air filter. This filter works well in cold cutting conditions, and is recommended when cutting in sub freezing temperatures that would ice up a fleece filter. We recommend using a fleece filter for hot, dusty situations where a lot of fine material is encountered. These are oil-less filters. These air filters will load up quickly because of the fine mesh, so we recommend having a couple of spares handy. Fits newer 029 and 039 chainsaws (see additional specs).