Dual Sub Box 1988-1998 GMC Sierra Extended Cab Xtreme Enclosures $225.29 Fits 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 foot Per Sub Mounting Depth = 5 1/4" Mounting Depth based on 6"... Choose Options
