The DONALDSON 18" x 12.09" OD nanofiber media type round primary air filter features advanced nanofiber media, capturing smaller particles to improve engine protection. Its round design integrates seamlessly into compatible air systems, providing a secure and effective seal. The filter is resistant to moisture, maintaining efficiency in damp conditions, and is engineered for high performance to support heavy duty use and prolonged engine life. Its consistent filtration efficiency aids in maintaining horsepower and torque by delivering cleaner air, ensuring reliable engine operation.