ASC Chevy Silverado or GMC Sierra Crew Cab Truck 2007-2013 Dual 12" Subwoofer Custom Fit Sub Box Speaker Enclosure Dimensions: Width 49-1/4" x Front Height 5" x Rear Height 9-1/4" x Depth 16-1/2" Install Location: Under Rear Seat Install Notes: No Modifications Required Mounting Depth: 5 Inches Air Space: 0.85 Cubic Feet