Closed Box Air Intake w/ Cold Air Scoop Red Filter 04-05 Silverado/Sierra 2500HD/3500HD VolantVolant air intake systems utilize a high velocity venturi filter adapter which provides a smooth transition through the MAF sensor into the intake tube for a much needed airflow improvement over the factory rubber tubing and resonator box. Volant's Cool Air box is larger than the factory unit and incorporates a larger opening to collect a higher volume of colder ambient air. Customers using the Volant CAI kit with the scoop report 2 4 MPG improvements