Q Power QBGMC10 2007 HT Dual 10-Inch Custom Fit Speaker Box for GM/Chevy Xcab Trucks 2007-2013 Dual 10" Sealed Under Seat Down Firing Unloaded Subwoofer Box For GMC/Chevy 2007-2013 Extended Cab High Transmission Trucks, Does NOT Fit Crew Cab Trucks This Enclosure is Constructed Out of High Grade 3/4" MDF Wood Covered and Finished with a Durable Bed Liner Coating and Equipped with Spring Loaded Terminals Internal Air Space: 0.62 Cubic Ft per Chamber