These air filter-specific K&N prefilters protect your motorcycle's air filter from the worst conditions.
Whether you're traversing the highway on a daily basis, or take your bike on an off-road adventure, dust and water will plague your air filter. These K&N prefilters literally provide an extra layer of protection. Made of sturdy polyester, the pre-filters allow for sufficient airflow to allow the main filter to do its job, while at the same time keeping out the bulk of the debris and water. It will definitely benefit the life span of your main air filter.
You can wash out the prefilters and treat them with a water-repellent product before reinstalling them.