HPS Performance 4.5" Air Filter, 9.5" Length, 7.75" Base, 5" Top, HPS-4328Key Features Manufactured using low pressure injection molding to effectively minimize seepage of rubber onto the filtering element. Improves air flow by up to 25% compared to filters manufactured using high pressure molding. Stainless steel mesh reinforcement to resist heavy suction over less rigid aluminum mesh. Specially formulated lightweight synthetic oil that will not affect or damage sensors. Filtering element traps particles as small as 5