Universal Perf. Air Filter

The K&N Engineering Universal Performance Air Filter (model RC-1250) is a reusable cotton air filter element designed for universal clamp-on applications across a wide range of engine sizes and configurations. This conical-design filter combines high air flow capacity with exceptional filtration efficiency, making it a proven choice for performance enthusiasts seeking a balance between engine breathing and intake cleanliness.

The filter's engineering centers on a 3.5-inch base diameter tapering to a 2-inch top diameter, with a total height of 4 inches and a 2.25-inch flange for secure mounting. The reusable cotton media is the defining feature—K&N's proprietary oiled cotton design captures contaminants while maintaining superior flow rates compared to traditional disposable paper elements. The conical geometry maximizes surface area within a compact footprint, reducing restriction while the oil-impregnated cotton trap fine particles without choking airflow. This design means longer service intervals and the ability to clean and re-oil the element rather than dispose of it, reducing long-term operating costs for users who perform regular maintenance.

This universal filter fits custom intake systems, performance builds, and aftermarket air intake kits where a clamp-on conical element is specified. It suits builders and tuners working on naturally aspirated engines who prioritize intake flow optimization without sacrificing protection. The reusable nature appeals to dedicated enthusiasts willing to maintain their filters—cleaning and re-oiling every 50,000 miles or as needed—to maximize both engine performance and component longevity. Weighing just 0.53 pounds, it adds negligible mass to the intake system.