Product Details: The Donaldson 51" Round Style 1 Muffler is designed to provide superior performance and durability. This muffler is manufactured with high-quality materials for long-lasting use. It is designed for a perfect fit and easy installation and helps to improve engine performance by reducing backpressure. It also offers increased fuel efficiency, reduced emissions and excellent noise reduction for a quieter operation. FleetPride is your First Click in Heavy Duty®.