K&N REPLACEMENT AIR FILTER Monster S2R/S4R
In the early 1960s, two motorcycle racers, Ken Johnson and Norm McDonald (K&N) developed a ground-breaking new idea for an air filter. After experimenting with numerous types of filter media, they discovered that an oiled cotton design allowed the filter to not only capture contaminants very efficiently, but also allowed it to be washed and reused, and the original K&N High-Flow Air Filter was born. Five decades later, K&N is still innovating industry-leading filtration technology. In addition to performance air filters, K&N® now manufactures a variety of other protection and performance products, including air intake systems, oil filters & fuel filters, with a reputation for exceptional quality and customer service.
This K&N racing air filter has just two layers of cotton to provide even lower air restriction than our replacement air filter for street vehicles. Unlike K&N replacement air filters, fuel management modifications will be necessary with this racing filter. K&N racing air filters are washable and reusable.
- Designed to increase horsepower and acceleration
- Designed for racing and track applications, not for street use
- Washable and reusable air filter
- Low restriction
- Filte Material: Cotton Gauze
- Washable: Yes
- Height: 24mm
- Outside Length: 279mm
- Outside Width: 217mm
- Filter Re-Oiling Amount: 33ml