This Stage-2 cold air intake system resulted in 30 max horsepower, 50 lbs. x ft. torque and out-flowed the factory intake by 48% on the 2011-2015 Chevrolet/GMC Diesel Trucks. This system intake tube incorporates an additional sensor pad for the factory humidity sensor found in the 2013-2015 Silverado HD/Sierra HD models. This system includes, a durable 18-gauge, powder-coated heat shield and features a washable/reusable conical Pro DRY S air filter for maximum flow. The Pro DRY S air filter uses three layers of progressively porosity synthetic "oil-free" media to provide maximum airflow for best performance results. This intake system also features a heat-insulating roto-molded plastic tube that replaces the stock intake tract and directs increased airflow with improved volumetric efficiency for maximum performance. This is a direct bolt-on kit that requires no cutting or drilling on OEM parts. One-Piece Filter Heat Shield: The air filter is housed in a one-piece, black powder-coated 18-gauge heat shield that minimizes warm engine air for maximum performance. The heat shield attaches to the lower half of the factory airbox to provide direct airflow to the filter.Roto-mold Tube:This system uses a C.A.D designed, dyno-tuned, roto-molded intake tube that achieves maximum airflow while maintaining a perfect fit. A sensor pad block-off plate is included to maintain fitment on early 2011-2012 Silverado HD/Sierra HD models.Large 7"x10" Oval Inverted Top Filter:This intake utilizes a large 7"x10" oval base filter oval inverted top. A 5-1/2" diameter opening provides for maximum airflow. This 3-layer progressively finer porosity synthetic "oil-free" media air filter provides maximum airflow for increased horsepower and torque.Hassle-Free Installation: aFe has developed this intake to provide a hassle-free installation that utilizes all factory mounting locations, minimizing the use of unnecessary hardware.Note: This intake system is not CARB exempt at this time and is not legal for sale in California or use on vehicles registered with the California Department of Motor Vehicles.