If you’re tinkering with your ride, whether it’s a race car, a snowmobile, or even a trusty generator, you might want to check out the K&N Universal Clamp-On Air Filter (RU-3690). This isn’t just any air filter; it’s built to fit a ton of different setups, so you can breathe new life into your machine without a major overhaul.
What sets this filter apart? For starters, it’s got a 6-inch diameter at the large end, making it a solid choice for a range of applications. The round tapered shape allows for better airflow, which means your engine can get the oxygen it craves. Plus, it’s made from durable cotton gauze, so you know it’s built to last. And when it gets dirty? Just wash it and reuse it—no need to toss it out and buy a new one.
The pliable rubber flange is another cool feature. It absorbs vibrations and ensures a snug fit, and it can stretch up to 1/16 of an inch (1.5mm) to fit those tricky in-between sizes. This means you can adapt it to various intake angles and diameters without a hitch. The flange has a 3.5-inch inside diameter and a length of 1.75 inches, which should work with a lot of setups out there.
Here’s a quick rundown of the specs:
This filter is not just about looks either; it's designed to enhance your engine's performance by improving airflow. And, let’s be real, who doesn’t want a little extra oomph? It’s perfect for those who like to push their machines to the limit—whether on the track or out in the snow.
So if you’re ready to upgrade your air intake system, the K&N Universal Air Filter is a solid choice. It’s reliable, easy to maintain, and versatile enough for a bunch of different applications. Give your engine what it needs and keep it running strong!
⚠ WARNING:
Cancer and Reproductive Harm
https://www.P65Warnings.ca.gov

K&N, formally known as K&N Engineering, Inc., is the world’s leading manufacturer of washable performance air filters and cold air intake systems. K&N manufactures over 12,000 parts for a wide range of makes and models of motorcycles, cars, SUV, trucks, industrial applications, and more. K&N was founded in 1969 and is headquartered in Riverside, California in a complex of 10 buildings compromising approximately 400,000 square feet. K&N also operates facilities in China, England, and the Netherlands.
In the early 1960s, two motorcycle racers, Ken Johnson and Norm McDonald (K&N) developed a revolutionary idea for an air filter—one that could perform under the demands of dusty, dirty off-road environments. After experimenting with different types of filter media, they discovered that an oiled cotton design allowed the filter to capture contaminants efficiently, and also be washed and reused. It was right then and there that the original K&N High-Flow Air Filter was born. Fifty years later, K&N is still dominating the industry with leading filtration technology and innovative products that offer extraordinary protection for virtually every application out there.
What Makes K&N the Best?All K&N products undergo rigorous testing to make sure they adhere to and exceed demanding quality standards. These tests include power, torque, and airflow tests to confirm that the intake products are maximizing power boost while retaining engine safety. The company stands behind its product 100 percent with some of the most extensive warranties in the business – a Million Mile Limited warranty. K&N’s performance air intake systems are designed to improve airflow to the engine by replacing the restrictive factory system with a single aerodynamic tube and highly efficient filter media. The systems are available in two materials. The first is Polyethylene, which is used to produce 57 and 63 series intake systems. The second one is aluminum, which can be found on the 69 and 77 series intake systems.
Advantages of K&N IntakesThe benefits of adding a K&N intake system to your car are plenty. Firstly, it will increase your vehicle’s horsepower and torque, while also improving fuel economy and the appearance of your engine bay. What’s more, it will deliver a satisfying, more aggressive exhaust note at higher RPMs. Each K&N intake includes an oversized filtering unit, which can go up to 100,000 miles between cleanings, unlike paper filters that can become clogged easily and cannot be washed or reused. In other words, with K&N products, you will never have to replace your air filter again.
Why Install an Aftermarket Intake?Internal combustion engines all work as large air pumps. Air goes in, fuel is added, combustion occurs, and air goes out. This means there are two ways of increasing power: getting more air into the engine or making it easier for air to get out of the engine. Your air intake is responsible for filtering air before it enters your engine. Dirty air can damage the engine cylinder walls, so a high-quality filter is a must-have item. With a K&N system or filter, you increase airflow through the filter, which means more air is pulled into the engine. K&N does this without reducing filtration qualities, so your engine will live a long life.
Purchase K&N Intakes at Vivid RacingVivid Racing carries an extensive inventory of K&N products ranging from air filters, oil filters, air injection systems, fuel filters and pumps, sensors, carburetors, cold air intakes, and much, much more! If you cannot find a particular item above, please call us at (480) 966-3040 and we will help you find it. We are also here to answer any product questions, regarding usage, benefits, and fitment. Don’t delay! Improve your vehicle’s performance today with K&N Intakes.
K&N Oil Filters | K&N Replacement Filters | K&N 57 Series Intakes | K&N 69 Series Typhoon Intakes
K&N 77 Series Intakes