The K&N RU-2815DK is a black Drycharger, a pre-filter wrap made from silicone-treated polyester that is made to cover K&N Air Filters. It is sized for the RU-2815 round tapered filter, with a 6-1/2 base diameter, 4-3/8 top diameter, and 8-3/4 height. The wrap's polyester mesh with uniform micron sized pores stops dirt particles as small as 0.005 inches (127 microns) before they reach the filter, and its treatment limits how much splashed water gets through. For a cold-air intake that sits low or in dusty, wet conditions, this is a way to keep the filter cleaner for longer, with extended service intervals between cleanings. Because the wrap is sized to a specific K&N filter rather than a generic sleeve, the custom fit gives it a better seat over the filter body than an oversized universal wrap.
Keep in mind that the wrap is water repellent, not waterproof. The manufacturer's wording is that the DryCharger is water repellent, not water proof, and the water repellent treatment is good for 1 to 2 years depending on conditions and usage. Search terms that match this part include K&N RU-2815DK drycharger wrap, RU-2815 pre-filter sock black, round tapered filter wrap 6.5 inch base, and K&N filter wrap dust and splash protection.
The manufacturer's round tapered wrap chart lists the RU-2815DK under the 6-1/2 inch base, 4-3/8 inch top, and 8-3/4 inch height dimensions. Those match the manufacturer's listing for the RU-2815 universal clamp-on filter, which has a 5 inch flange.
No. The manufacturer describes it as water repellent, designed to prevent splashes of water or mud from saturating the filter, but not as waterproof.
The manufacturer says K&N Drycharger wraps are meant to be run dry and can be cleaned with K&N air filter cleaner, so the wrap does not need to be oiled.
The wrap is a slip-on sleeve with stitched elastic openings, so it is fitted over the filter rather than mounted with hardware. The manufacturer's install sheet for this exact part was not located during research, so check the wrap's dimensions against your filter before fitting. Remove the filter from the intake, slide the wrap down over the filter body with the closed top facing up, and reseat the filter as normal. Because the water repellent treatment fades over time, inspect the wrap at each filter service and clean it with K&N air filter cleaner rather than soap or oil.
