ASC Chevy Silverado or GMC Sierra Full Size Extended Cab Truck 1999-2006 Dual 10" Subwoofer Kicker Square Sub Box Speaker Enclosure Dimensions: Width 55-1/4" x Front Height 12-1/2" x Rear Height 7" x Depth 19" Install Location: Under Rear Seat Install Notes: No Modifications Required Mounting Depth: 9 Inches Air Space: 1.40 Cubic Feet