K&N Dryflow Universal Clamp-On Air Filter RU-3112HBK — 4" Flange, 9" Tall, Dry Synthetic Washable, Oil-Free

K&N Dryflow RU-3112HBK is a reusable, clamp-on universal air filter with dry synthetic media designed to increase airflow and last the lifetime of your vehicle.

This clamp-on K&N Dryflow combines washable, oil-free filter media with a pliable rubber flange to deliver reliable filtration and easy installation across many applications. Built for performance and durability, it replaces disposable paper filters and reduces ongoing maintenance costs and waste. The RU-3112HBK specifically fits a 4-inch flange diameter, stands 9 inches tall, and has a 1.5-inch flange length, making it suitable for a wide range of aftermarket and custom intake setups.

How does this K&N Dryflow improve engine breathing?

The RU-3112HBK uses dual-layer dry synthetic media engineered to let more air flow into the intake while still trapping harmful particles. Increased airflow can support better throttle response and sustained power delivery under load without the mess of oiled filters.

• Dual-layer dry synthetic media for high airflow and contaminant capture
• Designed to enhance horsepower and acceleration potential
• Oil-free construction avoids residue on sensors and intake parts

What makes installation and fit simple for custom setups?

This model features an ultra-strong molded rubber flange that flexes to absorb vibration and clamps securely to a 4-inch inlet. Its universal clamp-on form factor and common dimensions let you drop it into many factory air boxes or attach it directly to aftermarket intakes.

• 4 in flange diameter and 1.5 in flange length for common intake sizes
• Pliable rubber flange provides a snug, vibration-resistant seal
• Clamp-on design requires only a standard hose clamp and basic tools

How do I maintain a dry synthetic K&N versus an oiled filter?

Dryflow filters are washable and do not require oiling after cleaning, simplifying maintenance and eliminating risk of over-oiling. Under normal highway driving the filter typically needs cleaning about every 50,000 miles, though dusty conditions call for more frequent checks.

• Wash and air-dry the filter media, no oil required
• Recommended inspection interval: roughly every 50,000 miles in typical driving
• Cleaning frequency increases in dusty or off-road environments

What durability and warranty protections does it offer?

The RU-3112HBK is built with premium materials and modern molding techniques to withstand repeated cleanings and long-term use. K&N backs its filters with a 1-year limited warranty and manufactures them in the USA for consistent quality control.

• Rugged construction for long service life and repeated cleaning cycles
• 1-year limited warranty for part defects under normal use
• Made in the USA to K&N quality standards

Who is this filter for? The K&N Dryflow RU-3112HBK suits drivers, mechanics, and builders who want a low-maintenance, high-flow clamp-on filter for custom or replacement intake setups. It’s ideal for enthusiasts seeking improved airflow without oil-related upkeep, fleet or daily drivers aiming to cut disposable-filter waste, and anyone needing a versatile, durable filter that fits standard 4" flange applications.