GS-JGM212B black 12" dual sealed sub box, fits 07-18 gmc sierra extended cab

SPECIFICATIONS: -CUTOUT DIAMETER: 11 1/8" -AIR VOLUME: 1.26 FT^3 -2 INDIVIDUAL CHAMBERS -VOLUME PER SUBWOOFER:  0.63 FT^3 -WEIGHT: 37 LBS. -MOUNTING DEPTH: 6 1/2" DIMENSIONS: -FRONT HEIGHT: 9 1/4" -REAR HEIGHT: 7 1/4” -LENGTH: 55 1/2" -DEPTH: 13 1/2" CONSTRUCTION: -5/8" HIGH QUALITY MDF WOOD -CARPETED WITH DURABLE TRUNK LINER FINISH -SEALED WITH HIGH QUALITY TITEBOND SILICONE -GLUED WITH HIGH QUALITY TITEBOND WOOD GLUE -2 BINDING POST TERMINALS INSTALLATION: -FITS UNDER REAR SEAT BEHIND THE DRIVER'S SIDE -DOWN FIRING -WILL NOT FIT 2007 CLASSIC