Atrend A182-12Cp B Box Series 12-Inch Dual Down-Fire Subwoofer Boxes Type: Enclosures Feature: Fits 2007 and Up GM Crew Cab MDF Construction Completely Carpeted Enclosure With Rounded Edges 0.75-inch Speaker Baffles Custom Built for Under Seat Application Dual 12 GM Crew Cab 2007 and up