Dual Sub Box 1988-1998 Chevy Silverado Extended Cab Xtreme Enclosures $201.15 1988-1998 CHEVROLET SILVERADO EXTENDED CAB AND 1988-1998 GMC SIERRA EXTENDED CAB Fits dual 8 or 10 inch subwoofers MDF construction Subs fire down Fits under rear seat Jack removal is required 1 1/4" clearance under the box Air Space = .75 cubic... Choose Options