How often should I clean this filter?

The cleaning interval depends on your driving conditions. Inspect the filter regularly, and clean it when you see a buildup of dirt and debris. Because it's a heavy-duty filter, it should last a while between cleanings.

What cleaning products should I use?

You can use power sprayers, pressure washers, or standard truck washing equipment to clean this filter. No special cleaning solutions or oils are needed. Just be sure to let it dry completely before reinstalling.

Is this filter street legal?

This filter is not CARB approved, so it is not legal for street use in California. Check your local regulations for compliance.

K&N Round Radial Seal 13-1/16in OD 7-9/16in ID 25-11/16in H Reverse Replacement Air Filter - HDT

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Specifications

Brand: K&N
Part #: 38-2021R
UPC: 024844277077

K&N Round Radial Seal 13-1/16in OD 7-9/16in ID 25-11/16in H Reverse Replacement Air Filter - HDT

Name: K&N Round Radial Seal 13-1/16in OD 7-9/16in ID 25-11/16in H Reverse Replacement Air Filter - HDT
Brand: K&N
Price: 451.99 USD
Availability: InStock

$451.99

On Backorder — Expected to ship by Apr 16, 2026

Order now to reserve yours — we'll ship as soon as stock arrives. Full refund if we're unable to fulfill.

Washable, reusable air filter for heavy duty applications. Improves performance and simplifies maintenance.

Key Features

Washable and reusable — saves money and reduces waste
Hybrid filtration medium — easy to clean
No oil required — simplifies maintenance
Well-built for heavy duty applications — long service life

⚠️ CA WARNING: This product can expose you to chemicals known to the State of California to cause cancer and/or birth defects or other reproductive harm. Learn more

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Product Details

K&N's line of Heavy Duty commercial grade air filters are washable and have been specially engineered for heavy duty trucks, RV's and agricultural equipment. They use a new hybrid filtration medium that's incredibly easy to clean. They can be washed using power sprayers, pressure washers or standard truck washing equipment and they do not require the use of oil. Instead of repeatedly throwing away expensive disposable air filters, now you have a choice. A washable air filter designed to improve engine performance will now make air filter maintenance a snap.