K&N High-Flow Universal Clamp-On Air Filter RC-4780 — 4" Flange, 9.5" Tapered, Washable Reusable

The K&N High-Flow Original Universal Clamp-On Air Filter (RC-4780) is a washable, reusable tapered clamp-on filter built to increase airflow and deliver lasting performance for many engine applications.

This clamp-on air filter from K&N combines multi-layer cotton gauze media with a molded rubber flange to create a durable, high-flow intake filter that’s designed for long-term use. With a 4-inch flange diameter, 1.6875-inch flange length and a 9.5-inch overall height in a round tapered shape, this model fits a wide range of custom and universal installations where increased airflow and a dependable seal are required.

How does this filter improve engine breathing without replacing factory parts?

The RC-4780 replaces disposable paper elements with a washable cotton-gauze filter that allows more clean air to pass into the intake. That increased airflow can enhance throttle response and support consistent engine performance while the durable flange provides a secure clamp-on attachment.

• High-flow multi-layer cotton gauze media for improved air passage
• Pre-oiled and ready to install—no extra prep needed
• Molded pliable rubber flange absorbs vibration and seals reliably
• Designed as a universal clamp-on for custom and replacement uses

How often will I need to clean or service this K&N clamp-on filter?

K&N filters are made to be cleaned and reused rather than frequently replaced. Under normal highway driving, cleaning is typically recommended around every 75,000 miles, but conditions like heavy dust or off-road use may require more frequent maintenance.

• Typical service interval: approximately every 75,000 miles in normal conditions
• Easy cleaning with K&N service kits or equivalent filter cleaner and oil
• Inspection recommended after exposure to heavy dust, mud, or water spray
• Lifetime use—designed to last the life of your vehicle with proper care

Will the clamp-on design fit my custom intake or aftermarket setup?

The RC-4780’s universal clamp-on flange makes it adaptable to many custom and aftermarket intakes that accept a 4-inch flange. The pliable rubber flange length helps accommodate small variations in fit, and its tapered shape suits cone-style intake layouts.

• Flange diameter: 4.00 inches—matches many clamp-on adapters
• Flange length: 1.6875 inches for a secure clamp seal
• Filter height: 9.5 inches, tapered round profile for space-efficient installation
• Works well with aftermarket pipes, velocity stacks, and custom airboxes

What materials and protections are built into this K&N air filter?

The RC-4780 uses multiple layers of treated cotton gauze to trap contaminants while allowing high airflow. The assembly includes a robust molded rubber flange and reinforced construction intended for long service life.

• Six-layer cotton gauze media treated to capture particles effectively
• Pre-oiled media to enhance initial filtration performance
• Durable molded rubber flange that resists vibration and warping
• Manufactured in the USA with a 1-year limited warranty

Who is this for: The K&N RC-4780 clamp-on air filter suits vehicle owners, hobbyists, and mechanics who want a reusable, high-flow intake solution for custom or universal applications. It’s ideal for people upgrading aftermarket intakes, building performance projects, or reducing recurring filter waste without changing factory housings where a 4-inch clamp-on connection is appropriate.