The 12" Dual Voice Coil Marine Subwoofer has a mounting depth of only 3.37". This is achieved by mounting its neodymium magnet in front of the cone. The magnet is housed in a custom polycarbonate cap with UV inhibitors. Its mica-filled polypropylene cone is joined to a large rubber surround, giving it a one-way excursion of 12.9mm. Both cone and surround also have UV inhibitors added for lasting durability. On the underside, the die-cast aluminum frame is finished in a flat black textured powder-coat. The dual 3" voice coils give the 1211 DVC Subwoofer a power rating of 400 watts RMS/800 watts peak. 20Hz - 220Hz frequency response. 4 ohm impedance per coil. Mounting depth: 3.37". Cutout: 11" dia. This package includes a polished stainless steel speaker grill and stainless mounting hardware.