The K&N RU-5171HBK is a universal clamp-on round tapered air filter, built on K&N's washable cotton gauze media. The manufacturer designs its universal filters for racing vehicles, snowmobiles, tractors, generators, and similar equipment, so this part suits custom intake builds more than a single factory application. Its molded rubber flange absorbs vibration and seals to the tube, and it can be stretched up to 1/16 of an inch to fit between standard sizes. Owners who want a reusable alternative to a disposable paper element can wash and re-oil this filter instead of replacing it, which the manufacturer presents as a way to reduce landfill waste.
Because this is a universal design, it is not sold as a vehicle-specific replacement. Measure the outside diameter of your intake tube and compare it with the flange inside diameter before ordering, and confirm the fit with the manufacturer if the sizes are close. Installation is mainly a matter of sliding the rubber flange onto the tube and tightening a clamp. The filter ships pre-oiled and ready to use. Search terms that match this product include K&N universal cone air filter for custom intake, RU-5171HBK clamp-on filter fitment, reusable cotton gauze intake filter, and washable K&N filter for tube-mount intakes.
The manufacturer describes its universal filters as designed for a range of applications rather than one vehicle. Fit depends on whether your intake tube matches the flange diameter.
The manufacturer states the flange can be stretched up to 1/16 of an inch (1.5 mm) to fit in-between sizes. Larger mismatches fall outside that range.
Installation is generally straightforward. Slide the centered rubber flange onto the intake tube, seat it fully, and secure it with a clamp. Check that the flange is not twisted and that the filter clears the surrounding engine bay or intake components. Confirm the tube diameter before you start, because a flange that is too far off will not seal properly even with the stretch allowance. Follow the cleaning and re-oiling instructions supplied with the filter when it needs maintenance.
