How to find your setup

Two ways in. If you run a stock or K&N airbox filter, use By Vehicle, pick your machine and the right cover is already paired. If you run an aftermarket carb with a clamp-on filter, use By Filter Size and match the flange (the inside diameter that slips over your carb spigot).

What the K&N letters mean

K&N part numbers tell you what kind of filter it is. The two letters come first, then a number that is just K&N's model ID (not a size).

Universal clamp-on filters (the letters describe the top / cap):

Vehicle-specific replacement filters (the letters are the brand):

So YA-3502 is a Yamaha replacement filter (it fits the Banshee), and RU-1720 is a rubber-top universal clamp-on. The digits after are just the model number.

Outerwears cover colors

Covers come in up to four colors. The letter on the end of the Outerwears part number is the color:

Example: 25-5811 is black, 25-5811B blue, 25-5811R red, 25-5811Y yellow. Not every fitment offers every color, the finder only shows the ones that exist.

What a pre-filter cover does

An Outerwears cover stretches over your air filter and blocks sand, dirt, and water before they reach the filter, so the filter lasts longer and stays cleaner. The silicone-treated micro-mesh filters particles down to .005" with no real loss of airflow, which is why it is a must-have for dune and desert riding.

Covers fit by size, not brand. We list the K&N filter as the reference because K&N publishes standard sizes, but the cover slips over any filter of that size the same way, whether it's your stock filter, a K&N, UNI, Twin Air, Maxima, or another brand we carry. Match the filter your machine takes and the cover follows.

Measuring for a universal filter

The flange size is the inside diameter of the filter's mounting flange, the opening that clamps over your carburetor or airbox spigot. Measure the outside diameter of that spigot and match it. The rubber flange stretches up to 1/8" (3mm) for in-between sizes.