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The K&N E-3640 universal round air filter is designed to deliver exceptional airflow and engine protection for a wide range of vehicles. Featuring a durable, layered oiled cotton media, this high-flow filter captures contaminants efficiently while boosting horsepower and overall engine performance. Its innovative design ensures optimal airflow, helping your engine breathe easier and operate more efficiently. Backed by K&N's 10-Year/Million Mile Limited Warranty, this reusable filter is built to last for the entire lifespan of your vehicle, making it a reliable upgrade for serious performance enthusiasts.
Installation is straightforward with the drop-in replacement design, which fits easily into your factory air box. The filter's dimensions, including a 9-inch outer diameter, 7-1/2-inch inner diameter, and 4-inch height, make it compatible with many custom and stock setups. The K&N E-3640 provides a substantial upgrade over standard paper filters, offering increased airflow and horsepower without sacrificing engine protection. Its durable construction ensures long-term use, and since it is washable and reusable, it reduces the need for frequent replacements, saving money and reducing waste.
Designed for automotive enthusiasts seeking an efficient, high-performance air filter, the K&N E-3640 is an excellent choice for improving engine response and power. It is not CARB approved, so check local regulations before installation, but it meets the highest standards of quality and performance. Invest in this premium K&N filter today and experience the difference in your vehicle's performance and longevity.
Features:
Order Processing
All orders are processed and shipped within 24 hours of purchase (excluding weekends and holidays).
Orders placed after 3:00 PM EST may ship the following business day.
Shipping Methods
Customers select their preferred shipping method and speed at checkout.
Shipping times are determined by the carrier and cannot be guaranteed by us.
Tracking information will be provided once your order has shipped.
Shipping Coverage
If your package arrives damaged, please notify the delivery driver immediately and contact the shipping carrier to file a claim.
You must report any missing or damaged items within 14 days of delivery.
After this time, we cannot be held responsible for lost or damaged items.
Return Window
You have 30 days from the date of delivery to request a return.
After 30 days, we are unable to accept returns, exchanges, or refund requests.
Eligibility
Items must be returned in their original condition—unused, unwashed, and with all tags and packaging intact.
Certain products may not be eligible for return (e.g., special-order items, customized products, or perishable goods).
Items that have been altered, installed, or modified cannot be returned.
Return Process
Contact our Customer Support team to request a Return Authorization (RMA) before sending items back.
Once your return is approved, you’ll receive instructions on where to send the product.
Customers are responsible for return shipping costs unless the item was defective or incorrect.
Refunds
Refunds are issued to the original payment method once the returned item has been received and inspected.
Please allow 5–10 business days for the refund to appear on your account.
In some cases, a restocking fee may apply (if applicable, this will be disclosed during your return authorization).
