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The K&N Engineering E-3804 Round High-Flow Air Filter features layered, oiled cotton media engineered to improve airflow while capturing contaminants. Designed as a performance replacement filter, it is intended to help increase horsepower while providing exceptional engine protection.
This washable and reusable air filter is engineered for long-term use and is designed to last for the lifespan of the vehicle. Its round design measures 16-1/4 inches outside diameter, 14-1/2 inches inside diameter, and 3-1/2 inches high.
The K&N E-3804 is designed to install easily into the factory air box and will not void the vehicle warranty. It is backed by K&N's 10-Year/Million Mile Limited Warranty and is covered by K&N's No-Hassle Lifetime Limited Warranty. Associated products include the 25-5300 Air Filter Foam Wrap and 99-5000 Filter Care Service Kit Aerosol.
This product is not CARB approved. A CARB acknowledgment is required.
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).
