Brand NEW Re Audio Srx12d4 12" 300 Watt Rms Rated (600w Peak) Dual Voice Coil 4 Ohm Car Subwoofer (Free Air or Small Enclosure Mounting Options) **Free Shipping** Engineered with new magnet covers that aid in cooling the voice coils while protecting the magnet 4-layer Copper Voice Coil FEA Optimized Motor Structure Mounting Hole Diameter - 11" Bolt Hole Circle - 11.625" Displacement - 0.14 cu. ft.