Uni Filter NU-4145ST Two-Stage Foam Air Filter for Honda Dirt Bikes

The Uni Filter NU-4145ST is a premium two-stage foam air filter engineered specifically for Honda dirt bikes. This high-performance replacement filter is designed to fit precisely in the factory airbox exactly like the original equipment filter, ensuring a perfect seal and optimal airflow.

Key Features:

• Unique two-stage foam design with dual layers that can be serviced separately for thorough cleaning
• Thin Ultra Seal foam base that is virtually tear-proof with integrated "Grease Groove" for superior sealing
• Drop-in replacement that fits the stock airbox perfectly without modifications
• Easy to clean and reusable design saves money over disposable paper filters
• Trusted by factory racing teams including Yamaha, Kawasaki, and Suzuki off-road programs
• Best-selling replacement air filter choice for competition motorcycles and ATVs

Uni Filter's dual-layer foam construction provides superior filtration while maintaining excellent airflow characteristics. The two-stage design allows each foam layer to be cleaned independently, ensuring complete removal of dirt and contaminants while extending filter life. The proprietary Ultra Seal base material resists tearing even under extreme conditions and features a built-in grease groove that creates a secure, leak-free seal against the airbox.