2007-2013 Chevy Silverado/GMC Sierra Crew Cab Dual 12" Sub Box | Skar Audio
DEEP Sub box- 2007-2013 Chevy Silverado/GM Sierra Crew Dual Box - Sound Off Audio, Inc.
89-1998 Chevy Silverado Extended Cab Sub Box 8" Single Subwoofer Box Enclosure | eBay
Amazon.com: American Sound Connection Compatible with Chevy Silverado or GMC Sierra Full Size Extended Cab Truck 2007-2013 Dual 12" Subwoofer Sub Box Speaker Enclosure : Electronics