Fit this over your Twin Air Filter when you’re riding in severe conditions such as heavy dust and sand. This coarse foam pre-filter, oiled for maximum benefit, will act as an additional layer of protection and extend the service time between filter cleanings. RAIN COAT AIRFILTER KAWASAKI KX250F 21-24 KX450F 19-23 KX250XC 21-24 KX450XC 21-23