K&N Engineering K&N Universal Custom Air Filter - Oval - Red - 8.813 L x 6.188in W x 2.25in H RT-3910

KN Custom Air Filter

Air Cleaner Assembly

The K&N RT-3910 Custom Air Filter converts the RK-Series Air Filter Assembly (RK-3909) with a taller K&N Air Filter and longer spacers. It is designed for Harley owners who need more air for better performance.