Rockford Fosgate Punch P1S415 15-Inch 400 Watt SubWoofer - 4 Ohm 15-inch, 4-ohm sub woofer with 400 watts power handling Thermoformed polypropylene cone with high-density poly-foam surround High-temp voice coil with spun-laced Nomex re-inforcement collar Sealed box volume: 1.3-3.5 cubic feet Ported box volume: 2.66 cubic feet