K & N Air Filter - EX400 Ninja KA-4018

A stock air filter is your engine's first line of defense—and often its first compromise. The K&N EX400 Ninja KA-4018 replaces that restriction with engineered filtration that flows more freely while protecting your engine, letting your Ninja breathe and respond the way it was meant to. Better airflow translates directly to measurable performance gains without touching your fuel maps or breaking your budget on tuning.

This is a purpose-built filter engineered specifically for your bike, not a universal compromise. The application-specific sealing bead locks into your OEM airbox with zero guesswork, and the pleated media design extends service intervals while maximizing filtration area. It's the bolt-on upgrade that actually delivers.

• Fits EX400 Ninja directly
• OEM airbox compatible
• Application-specific sealing bead
• Pleated filtration media
• Extended service intervals
• No fuel tuning required
• Increased airflow performance
• Made in U.S.A.
• Bolt-on installation
• MPN: KA-4018