The K&N Drycharger Air Filter Wrap in black (MPN RX-4730DK) is a slip-on pre-filter sleeve for K&N intake filters. The manufacturer describes the Drycharger as a silicone-treated polyester wrap designed to cover K&N air filters or personal watercraft flame arrestors. Its openings are uniform and micron-sized, and the manufacturer notes they are similar to K&N Prechargers. Searches for K&N RX-4730DK wrap, silicone-treated pre-filter sock, and K&N clamp-on pre-filter cover tend to land on this exact part.
The purchase case is protection for the filter element itself. The outer layer catches dust and debris before it reaches the cotton media, which can extend the time between cleanings on dusty roads or gravel tracks. The silicone treatment limits how much water reaches the air filter or flame arrestor. For a driver who sees rain, puddles, or wet event days, that is a practical reason to add a wrap rather than rely on the bare filter alone.
Dimensions are a 6-inch base inside diameter, a 5-inch top inside diameter, and a 6.5-inch height, with a closed top. The wrap is sold as a round tapered shape with a closed top. Confirm the base diameter against your filter before ordering, since a wrap that does not match will not seat properly. Installation is a slip-on step: the stitched elastic opening holds the wrap snug on the filter, so you can add or remove it during routine cleaning without tools.
