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

K&N High-Flow Original Lifetime Universal Clamp-On Air Filter (RC-4780) is a washable, reusable, performance-oriented clamp-on filter with a 4" flange and 9.5" height built to increase airflow and last for the life of your vehicle.

This tapered clamp-on air filter from K&N is designed as a universal upgrade for many intake systems that accept clamp-style filters. Constructed with multilayer cotton-gauze media and a pliable molded rubber flange, it aims to improve airflow and throttle response versus conventional paper elements while reducing replacement waste. The RC-4780 combines rugged materials, pre-oiled readiness, and an easy clamp-on installation that suits hobbyists, racers, and everyday drivers who want a durable, long-lived filtration solution.

How does this filter improve engine airflow and performance?

The K&N high-flow media uses multiple layers of oiled cotton gauze to permit greater air volume while still capturing contaminants. Increased airflow can support improved acceleration and responsiveness when paired with a compatible intake and tuning. This filter is engineered to balance filtration efficiency with minimal flow restriction.

• Six layers of premium cotton gauze treated for dust capture
• Designed to increase horsepower and acceleration potential
• Pre-oiled and ready to install for immediate use
• Round tapered (cone-style) shape that promotes smoother intake flow

What are the physical dimensions and fitment details I need to know?

The RC-4780 is a tapered round clamp-on filter with a 4-inch flange diameter and a total filter height of 9.5 inches, making it suitable for many aftermarket and custom intakes. The flange length and pliable rubber allow the filter to seat securely and absorb vibration, simplifying attachment to a hose or intake tube. Use the dimensions to verify clearance and clamp compatibility before purchase.

• Flange diameter: 4.00 inches (suitable for standard clamp-on hoses)
• Filter height: 9.5 inches for generous filtering surface area
• Flange length: 1.6875 inches with flexible molded rubber
• Shape: round tapered (cone-style) for compact intake packaging

How do I maintain this filter and how often does it need cleaning?

K&N washable filters are designed for periodic cleaning and re-oiling instead of frequent replacement. Under typical highway driving, K&N recommends cleaning roughly every 75,000 miles, which can translate to multi-year service for average drivers. When cleaning is needed, follow K&N’s cleaning kit procedure to preserve filtration performance and media integrity.

• Clean approximately every 75,000 miles under normal highway conditions
• Use K&N cleaner and re-oil kit for best results and longevity
• Inspect seal and flange for tears or deformation during service
• Reusable design reduces disposable filter waste and long-term cost

Is this filter durable and covered by warranty?

The RC-4780 is built with reinforced materials—a molded pliable rubber flange and robust media layers—intended for long-term use in a variety of environments. K&N assembles these filters in the USA and backs them with a limited warranty, reflecting confidence in manufacturing quality. Regular inspection and proper maintenance will help the filter deliver extended service life.

• Durable molded rubber flange absorbs vibration for secure fit
• Premium construction designed for lifetime use with maintenance
• 1-year limited warranty from K&N for manufacturing coverage
• Made in the USA with consistent quality controls

Who is this for: The K&N RC-4780 clamp-on air filter is ideal for vehicle owners, fabricators, and mechanics who need a universal, high-flow cone-style filter for performance applications or custom intakes. It suits people who prefer reusable components, plan for long-term ownership, and want an easy-to-install upgrade that reduces landfill waste compared with disposable filters.