Metra 12" Single Ported Subwoofer Enclosure for Most Trucks and SUVs Charcoal TCTSP-112 - Best Buy
Amazon.com: American Sound Connection Compatible with Ford F150 Extended Super Cab Truck 2004-2008 Dual 10" Subwoofer Sub Box Speaker Enclosure : Electronics
Dual 12" Subwoofer Regular Standard Cab Truck Sub Box Enclosure Speaker Audio | eBay