The Baldwin RS3539 Air Filter traps dirt and debris before it reaches your engine's sensitive components. 3-3/4 Inch Dust Ejector Hole ---Heavy-Duty Radial Seal Gasket and End Cap will not degrade under temperature extremes, changes in restriction or vibration ---Flexible Outer Edges makes for easy installation and removal in housings with minimal clearance ---PermaPleat Construction provides even pleat spacing to prevent bunching and prolong element life ---Spiral Glue Binding provides added pleat stability for peak media effectiveness Application Summary: Freightliner, Kenworth, Peterbilt, Western Star Trucks Cross Reference: Donaldson P534816.