{"product_id":"k-n-high-flow-clamp-on-air-filter-ru-4740-4-5-inch-flange-6-inch-tapered-washable-reusable","title":"K\u0026N High-Flow Clamp-On Air Filter RU-4740 — 4.5-inch Flange, 6-inch Tapered Washable Reusable","description":"\u003cp\u003e\u003cstrong\u003eK\u0026amp;N High-Flow Original Universal Clamp-On Air Filter RU-4740 is a washable, reusable tapered clamp-on filter that increases airflow while providing durable, long-lasting engine protection.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThis K\u0026amp;N clamp-on air filter is built to fit a wide range of intake setups and offers performance-minded drivers a reusable alternative to disposable paper elements. The RU-4740 features a 4.5-inch molded rubber flange and a 6-inch overall height in a round, tapered (cone-style) shape that works for many custom and replacement applications. Pre-oiled and ready to install, it’s engineered to let more air reach the engine without sacrificing filtration quality.\u003c\/p\u003e\n\n\u003ch3\u003eHow does this filter affect engine breathing and performance?\u003c\/h3\u003e\n\u003cp\u003eThe multi-layer cotton gauze media is designed to move more air into the intake than a typical paper filter, which can translate to improved throttle response and potential horsepower gains on many engines. K\u0026amp;N achieves increased flow by using a dense but porous cotton mesh treated with a tackifier that helps trap contaminants without overly restricting airflow.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFour-layer cotton gauze construction for enhanced airflow and filtration.\u003c\/li\u003e\n  \u003cli\u003ePre-oiled media ready to catch particles after installation.\u003c\/li\u003e\n  \u003cli\u003eTapered cone shape encourages smooth intake flow into the throttle body.\u003c\/li\u003e\n  \u003cli\u003eEngineered to maintain airflow as the element collects debris.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWill the RU-4740 fit my setup and how easy is installation?\u003c\/h3\u003e\n\u003cp\u003eThis clamp-on filter is made with a pliable molded rubber flange that compresses to fit onto 4.5-inch diameter inlets and absorbs vibration for a secure fit. Because it’s a universal-style clamp-on unit, it’s common in custom air-intake builds, replacement airboxes, and aftermarket intake tubes where a tapered filter is required.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e4.5 in flange diameter, 0.625 in flange length for secure clamp mounting.\u003c\/li\u003e\n  \u003cli\u003e6 in overall height and round tapered profile fits many cone-style applications.\u003c\/li\u003e\n  \u003cli\u003ePliable rubber flange simplifies mounting to varied tubing finishes and angles.\u003c\/li\u003e\n  \u003cli\u003ePre-oiled: no initial oiling step required for most installations.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow does maintenance work and what is the service interval?\u003c\/h3\u003e\n\u003cp\u003eK\u0026amp;N filters are washable and reusable, which reduces recurring costs and landfill waste compared with disposable filters. For normal highway driving, K\u0026amp;N recommends cleaning approximately every 75,000 miles, but frequency should increase with dusty or off-road use.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eWash and re-oil procedure uses K\u0026amp;N cleaning kit or compatible products.\u003c\/li\u003e\n  \u003cli\u003eTypical cleaning interval: up to 75,000 miles under normal highway conditions.\u003c\/li\u003e\n  \u003cli\u003eInspect more often in dusty\/off-road environments to protect the engine.\u003c\/li\u003e\n  \u003cli\u003eDurable construction intended to last for the life of your vehicle.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this product for?\u003c\/p\u003e\n\u003cp\u003eThe K\u0026amp;N RU-4740 is aimed at vehicle owners, hobbyists, and performance enthusiasts who want a universal clamp-on cone filter that improves airflow, cuts long-term filter costs, and reduces landfill waste. It’s a good choice for custom intakes, replacement applications requiring a 4.5-inch flange, and anyone who prefers a washable, durable filter built in the USA with a manufacturer-backed warranty.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: What flange size does the RU-4740 use?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: The RU-4740 has a 4.5-inch flange diameter with a 0.625-inch flange length for clamp mounting.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: How often should I clean this K\u0026amp;N filter?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Under normal highway driving, clean about every 75,000 miles; clean more often in dusty or off-road conditions.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"K\u0026N","offers":[{"title":"Default Title","offer_id":48084145733790,"sku":"B000630I26","price":87.78,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/k-and-n-ru-4740-front-view.jpg?v=1785847356","url":"https:\/\/northtrailauto.ca\/products\/k-n-high-flow-clamp-on-air-filter-ru-4740-4-5-inch-flange-6-inch-tapered-washable-reusable","provider":"North Trail Auto","version":"1.0","type":"link"}