For Nissian Altima/Maxima L31 Aluminum Cold Air Intake Induction Pipe+Red Filter Made of High Quality T-6061 Aluminum Material for Strength and Durability Lightweight High Air Flow Racing Performance Spec. Design 3" OD Diameter Piping (Reuse OEM Maf Sensor for Installation) Helps Engine to Draw In More and Colder Air Resulting In Better Throttle Response and Higher Explosive Horsepower Output Improves Up to 95% Filtration Efficiency / Increases 5 to 10 Horsepower, 6% to 8% of Torque