The 50 Series HD Heavy Duty Muffler is built tough for trucks, featuring 4.00-inch internal components and a large case size. Designed to boost mileage, torque, horsepower, and towing power, it enhances acceleration for both gas and diesel applications. Perfect for late-model trucks used in extreme conditions, the 50 Series HD delivers outstanding performance and durability, making it the ideal choice for heavy-duty applications.