Take your diesel engine to the next level …with this genuine Walker high performance air filter. This is the replacement air filter element for marine gensets and auxiliary engines equipped with the Walker Universal Genset AIRSEP. 5.5" diameter x 4" long Washable and Reusable Resists clogging from moisture or oil Shipped ready to use Walker Part# CD171ACommonly found on marine genset engines such as Onan, Kohler and Northern Lights, as well as small auxiliary engines such as a Perkins 4108 series equipped with Walker AIRSEP.