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K&N RU-4250 universal clamp-on air filter fits racing vehicles radio-controlled cars generators snowmobiles tractors and custom intakes regardless of angle or offset. Molded rubber flanges absorb vibration stretch up to 1/16 inch for secure fit. Washable reusable design traps contaminants while boosting airflow for more horsepower and acceleration.
Key Features
- 3.75in flange inside diameter with 5.375in base OD 4.375in top OD 5in height suits tapered custom intakes.
- Easy Installation: Pre-oiled ready-to-use clamp-on design delivers quick performance gains with minimal effort.
- Engineered Power: Advanced filter media increases airflow for higher horsepower acceleration and engine response.
- Clamp-on rubber flange secures to 3.75in ID intake stretches slightly for precise fit.
- High-flow oiled media outperforms paper filters in airflow and filtration.
- Re-oil after cleaning using K&N air filter oil for peak performance.
Fitment
| Fitment Status | Universal or dimensional product |
|---|---|
| Required Verification | Exact dimensions, media, connection, mounting interface, and companion part number |
Specifications
| Brand | K&N Engineering |
|---|---|
| Manufacturer Part Number | RU-4250 |
| Product Type | Air Filters - Universal Fit |
| Fitment Type | Universal |
| Condition | New |
What's Included
One new K&N air filters - universal fit identified by manufacturer part number RU-4250. Hardware, adapters, clamps, hoses, filters, and service supplies are included only when stated for this exact product.
About K&N Engineering
K&N develops reusable air filtration, intake, oil filtration, fuel filtration, and related performance products for vehicle-specific and dimensional applications.
Related K&N Engineering Products
- Shop all K&N Engineering products
- K&N Universal Rubber Filter 2 nch Top OD / 3.5 inch Base OD / 2.25 inch Flange ID / 4 inch Height
- K&N Universal Rubber Filter 2.75in Flange ID x 5.875in Base OD x 4.75in Top OD x 7in Height
- K&N Universal Rubber Filter 4.5in Flange ID / 5.875in Base OD / 5.125in Top OD / 5in Height
Frequently Asked Questions
How do I confirm K&N RU-4250 fits my setup?
Match every listed dimension, flange or thread size, media type, mounting interface, and companion component. A similar shape or outside dimension alone does not confirm compatibility.
Is K&N RU-4250 washable and reusable?
Serviceability depends on the exact media used for this part number. Follow the K&N cleaning and oiling directions for this filter and never apply oil to media specified as dry.
What should be checked after installing K&N RU-4250?
Verify seals, clamps, fasteners, hoses, sensors, wiring, and surrounding clearance as applicable. Check for leaks or contact, then follow the manufacturer service and reinspection schedule.
Installation Instructions
- Clamp-on rubber flange secures to 3.75in ID intake stretches slightly for precise fit.
- Compatible with custom air intakes no additional hardware required.
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