2001-2007 Chevy Crew Cab Poly Non HD Subwoofer BoxFits 2001 2007 Chevy Crew Cab Non HD 1500 The hardest hit sub box for the Chevy Crew Cab Armor Coated With High Pressure Polyurethane Bed Liner Material Increases The Base, up to 300% stiffens the wood and no air leaks 2 10'' Speakers Fits under the back seat Down Firing System Air Volume . 6 Cubic Feet Per Side Mounting Depth 4. 5'' Material 5 8'' M. D. F Speaker terminal is included Magnet diameter not more than 5'' 1. 5'' clearance under the box