{"product_id":"k-n-universal-custom-air-filter-oval-shape-9-313in-od-2-375-height","title":"K\u0026N Universal Custom Oval Air Filter — 9.313in OD x 2.375in H High-Flow (RK Series Replacement)","description":"\u003cdiv style=\"background:#f7f7f7;border-left:4px solid #c00000;padding:14px 18px;margin:0 0 18px;\"\u003e\n\u003ch3 style=\"margin:0 0 6px;font-size:1.1em;\"\u003eAbout K\u0026amp;N Engineering\u003c\/h3\u003e\n\u003cp style=\"margin:0;font-size:0.95em;line-height:1.55;\"\u003eK\u0026amp;N has been the world's leader in washable, reusable performance air filters since 1969. From the legendary cone filter to complete cold-air intake systems, K\u0026amp;N's cotton-gauze element delivers more airflow than paper while staying serviceable for the life of the vehicle.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003ch3 style=\"margin:24px 0 8px;\"\u003eWatch in action\u003c\/h3\u003e\u003cdiv style=\"position:relative;padding-bottom:56.25%;height:0;overflow:hidden;margin:0 0 18px;border-radius:6px;\"\u003e\u003ciframe src=\"https:\/\/www.youtube.com\/embed\/YOznRtb-1ME\" style=\"position:absolute;top:0;left:0;width:100%;height:100%;border:0;\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen loading=\"lazy\"\u003e\u003c\/iframe\u003e\u003c\/div\u003e\n\u003ch2\u003eK\u0026amp;N E-3988 Universal Custom Oval High-Flow Air Filter\u003c\/h2\u003e\u003cp\u003eUpgrade your RK Series air cleaner assembly with the K\u0026amp;N E-3988 Universal Custom Oval Air Filter. This high-performance filter is specifically designed to increase horsepower and acceleration, providing superior airflow while maintaining excellent filtration efficiency. With a 9.313-inch outer diameter and 2.375-inch height, it's an ideal replacement for specific K\u0026amp;N RK Series units, particularly for Harley-Davidson motorcycles.\u003c\/p\u003e\u003ch3\u003eDesigned for Performance and Longevity\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eOptimized Airflow:\u003c\/strong\u003e K\u0026amp;N's renowned layered, oiled cotton media maximizes air intake for improved engine response and power.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEngine Protection:\u003c\/strong\u003e Effectively captures harmful contaminants, ensuring the longevity and health of your engine.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWashable \u0026amp; Reusable:\u003c\/strong\u003e This filter offers exceptional long-term value, being fully washable and reusable for the life of your vehicle.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMillion-Mile Warranty:\u003c\/strong\u003e Backed by K\u0026amp;N's famous Million-Mile Limited Warranty, guaranteeing quality and durability.\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eWhether you're replacing a worn filter or upgrading for better performance, the K\u0026amp;N E-3988 delivers. Experience the difference of K\u0026amp;N's advanced filtration technology and unleash your engine's potential. Available now at GGCRACING.\u003c\/p\u003e\n\u003cdiv style=\"margin:24px 0;border-top:1px solid #eee;padding-top:18px;\"\u003e\n\u003ch3 style=\"margin:0 0 6px;\"\u003eOften bought with\u003c\/h3\u003e\n\u003cp style=\"font-size:0.9em;color:#555;margin:0 0 8px;\"\u003eOther popular K\u0026amp;N Engineering products customers consider together:\u003c\/p\u003e\n\u003cul style=\"padding-left:20px;margin:0;\"\u003e\n\u003cli style=\"margin:4px 0;\"\u003e\u003ca href=\"https:\/\/ggcracing.com\/products\/k-n-custom-racing-assembly-carbon-fiber-air-box-w-o-base-large\" style=\"color:#0066cc;text-decoration:none;\"\u003eK\u0026amp;N Custom Racing Assembly Carbon Fiber Air Box - Large\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:4px 0;\"\u003e\u003ca href=\"https:\/\/ggcracing.com\/products\/k-n-custom-racing-assembly-carbon-fiber-air-box-large-solid-base-only\" style=\"color:#0066cc;text-decoration:none;\"\u003eK\u0026amp;N Custom Racing Assembly Carbon Fiber Air Box - Large Solid Base\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:4px 0;\"\u003e\u003ca href=\"https:\/\/ggcracing.com\/products\/k-n-custom-racing-assembly-carbon-fiber-4in-air-box-w-o-base-large\" style=\"color:#0066cc;text-decoration:none;\"\u003eK\u0026amp;N 100-8591 Custom Racing Carbon Fiber Air Box - Large\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:4px 0;\"\u003e\u003ca href=\"https:\/\/ggcracing.com\/products\/k-n-custom-racing-air-filter-rectangular-carbon-fiber-4in-air-box-w-2-75in-air-horn\" style=\"color:#0066cc;text-decoration:none;\"\u003eK\u0026amp;N 100-8593 Custom Racing Air Filter - Carbon Fiber 4in Air Box w\/ 2.75in Air Horn\u003c\/a\u003e\u003c\/li\u003e\n\u003cli style=\"margin:4px 0;\"\u003e\u003ca href=\"https:\/\/ggcracing.com\/products\/k-n-ford-gm-dodge-throttle-control-module\" style=\"color:#0066cc;text-decoration:none;\"\u003eK\u0026amp;N 20-1000 Throttle Control Module — Fits Ford, GM, Dodge\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\":\"https:\/\/schema.org\/\",\"@type\":\"Product\",\"name\":\"K\u0026N Universal Custom Oval Air Filter \\u2014 9.313in OD x 2.375in H High-Flow (RK Series Replacement)\",\"description\":\"Enhance airflow and horsepower with the K\u0026N E-3988 universal oval air filter, designed for RK Series air cleaner assemblies. Shop at GGCRACING!\",\"brand\":{\"@type\":\"Brand\",\"name\":\"K\u0026N Engineering\"},\"mpn\":\"E-3988\",\"url\":\"https:\/\/ggcracing.com\/products\/k-n-universal-custom-air-filter-oval-shape-9-313in-od-2-375-height\",\"offers\":{\"@type\":\"Offer\",\"price\":\"64.99\",\"priceCurrency\":\"USD\",\"availability\":\"https:\/\/schema.org\/InStock\",\"url\":\"https:\/\/ggcracing.com\/products\/k-n-universal-custom-air-filter-oval-shape-9-313in-od-2-375-height\",\"sku\":\"KNNE-3988\"}}\u003c\/script\u003e\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\":\"https:\/\/schema.org\",\"@type\":\"BreadcrumbList\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/ggcracing.com\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Intake\",\"item\":\"https:\/\/ggcracing.com\/collections\/intake\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"K\u0026N Engineering\",\"item\":\"https:\/\/ggcracing.com\/collections\/vendors?q=K\u0026N+Engineering\"},{\"@type\":\"ListItem\",\"position\":4,\"name\":\"K\u0026N Universal Custom Oval Air Filter \\u2014 9.313in OD x 2.375in H High-Flow (RK Series Replacement)\",\"item\":\"https:\/\/ggcracing.com\/products\/k-n-universal-custom-air-filter-oval-shape-9-313in-od-2-375-height\"}]}\u003c\/script\u003e\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\":\"https:\/\/schema.org\",\"@type\":\"FAQPage\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"Does the K\u0026N Universal Custom Oval Air Filter \\u2014 9.313in OD x 2.375in H High-Flow (RK Seri fit my vehicle?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Compatibility depends on your exact year, make, and model. Contact our experts at GGCRACING with your VIN and we'll verify before you order.\"}},{\"@type\":\"Question\",\"name\":\"How long is shipping for K\u0026N Engineering?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Most in-stock items ship same or next business day. Free shipping on orders over $99 in the continental US. Tracking is provided via email as soon as your order leaves our warehouse.\"}},{\"@type\":\"Question\",\"name\":\"How do I install the K\u0026N Universal Custom Oval Air Filter \\u2014 9.313in OD x 2.375in H High-Flow (RK Seri?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Cold air intakes typically install in 30-60 minutes with basic hand tools. No tuning required for most plug-and-play kits.\"}}]}\u003c\/script\u003e","brand":"K\u0026N Engineering","offers":[{"title":"Default Title","offer_id":41456443883604,"sku":"KNNE-3988","price":64.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0552\/3210\/2484\/files\/13b18d86053bb596e48380629d3640c3.jpg?v=1721692855","url":"https:\/\/ggcracing.com\/en-co\/products\/k-n-universal-custom-air-filter-oval-shape-9-313in-od-2-375-height","provider":"GGCRACING INC","version":"1.0","type":"link"}