K&N air filter cleaning set with oil in spray bottle.
The large spray bottle (355ml, Item No. 99-0606) is intended for cleaning the air filter.
After approx. 10 minutes soaking with the cleaning agent, the filter should be rinsed from the inside with (lukewarm) water.
Then the air filter must dry (natural drying!).
Once completely dry, the air filter can be sprayed with (red) oil using the spray bottle (237ml, Art.no. 99-0533).

Annual cleaning of the air filters is highly recommended!
It is precisely the oil that ensures the filtering of dirt (not the fiber cloth).