The K& N E-4527 Air Filter is an oil-free, synthetic direct replacement filter for select Bolens, Gehl, Midland, Onan, and Wisconsin/Robin models. This air filter is intended specifically for small engine and light industrial applications. K& N air filters provide high air flow while maintaining excellent filtration. The reduced restriction allows your engine to breathe more efficiently. K& N air filters are washable and reusable.