Kevin its kind of like nylon, it has very small holes in it to let air in but to keep the dirt out of the main vent tube , the vent tube comes out very easily but those little white stone/plugs sometimes donot and on some of the earlier saw had 2 of them, this doesnot work at all in the deep snow or on days that are freezing but real cold in deep snow as those white stone/plug freeze solid and donot let any air in at all ,, husky is not the only saw to have vent trouble in deep snow . I know I have done my fair share or work on stihls to
