K&N's Universal Air Filters are designed and manufactured for a wide variety of applications including racing vehicles, radio-controlled cars, generators, snowmobiles, tractors, and other applications. Regardless of the angle or offset diameter of the air intake, there is probably a K&N Universal air filter for your equipment. All filters are constructed with ultra-strong molded pliable rubber flanges which absorb vibration and allow for secure attachment and can also be stretched for up to 1/16 of an inch (1.5mm) to fit in-between sizes. K&N universal air filters are washable and reusable.
- ENGINEERED POWER: State-of-the-art air filter media is designed to increase horsepower and acceleration as well as improve overall engine performance
| Attributes | |
| Air Filter Color | Red |
| Air Filter Large End Diameter | 5 in (127 mm) |
| Air Filter Material | Cotton Gauze |
| Air Filter Shape | Round Tapered |
| Alternate Part Number | RU-3870 |
| Automotive Item Grade | High Performance |
| Base Outside Diameter | 5 in (127 mm) |
| California Proposition 65 | WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov |
| Country of Origin (Primary) | US |
| Emission Code | Legal US |
| Filter Material | Cotton Gauze |
| Filter Re-Oiling Amount | 0.88 oz (26 ml) |
| Flange Angle | 0 degrees |
| Flange Inside Diameter | 3 in (76 mm) |
| Flange Length | 1.75 in (44 mm) |
| Flange Offset | 0 in (0 mm) |
| Flange Type | Centered |
| Flanges | 1 |
| Frame Design | Flexible |
| GTIN | 00024844373663 |
| Harmonized Tariff Code (Schedule B) | 8421310000 |
| Hazardous Material Code | N |
| Height | 5 in (127 mm) |
| Item Height | 5.000 in. (127mm) |
| Item Type | High Performance |
| Item Weight | 1.200 lbs. (0.6 kg) |
| Life Cycle Status Code | Available to Order |
| Machine Washable | Yes |
| NAFTA Preference Criterion Code | B |
| Number of Flanges | 1 |
| Oil Included | Yes |
| Overall Filter Efficiency | Up To 99% Efficiency |
| Package Contents | 1 Air Filter |
| Package Material | Corrugated |
| Package Quantity | 1 |
| Package Type | Box |
| Pre-Screened | No |
| Product Style | Round Tapered Universal Air Filter |
| SDR Required Flag | N |
| Shape | Round Tapered |
| Top Material | Rubber |
| Top Outside Diameter | 4.5 in (114 mm) |
| Top Style | Rubber |
| Warranty | 1 Year Limited |
| Washable | Yes |
| Weight | 1.2 lb (0.6 kg) |
K&N RU-3870 Universal Clamp-On Air Filter
Product Information
- Brand: K&N
- Product Number: RU-3870
- Availability: Call for Availability

















