For Silverado/Sierra GMT800 6.6 Diesel Black Coated Aluminum Air Intake Pipe+Red Filter System Made of High Quality T-6061 Aluminum Material for Strength and Durability Lightweight High Air Flow Racing Performance Spec. Design Helps Engine to Draw in More and Colder Air Resulting in Better Throttle Response and Higher Explosive Horspower Output Improves Up to 95% Filtration Efficiency; Increases 5 - 10 Horsepower, 6 - 8% of Torque, and Improve the Gas Mileage Intake Inlet Size: 3.5"