99-06 Chevy Silverado/GMC Sierra Regular Cab Dual 10 Subwoofer Box with Amp Space Fits 1999-2006 Chevy Silverado and GMC Sierra Regular Cab Trucks Holds Two 10" Subs, Amp Shelf: 18"W x 13"H Mounting Depth: 6.25", Volume: .85 cu.ft./Spkr, Sealed, Mounting Hole: 9-1/8" No modifications to the vehicle are required, unit drops in Finish: Charcoal Gray Carpet as shown, Speaker terminals installed