Skar Audio DDX-15 D4 15" 1,500 Watt Max Power Dual 4 Ohm Car Subwoofer 15-inch Dual 4 Ohm Competition Grade Car Subwoofer Peak Power: 1,500 Watts | RMS Power: 1,000 Watts Massive Double Stack Magnet & High Temperature 2.5" Copper Voice Coil Competition Grade Paper Cone and High Roll Foam Surround Advanced Air Flow Cooling Design | Fs: 41.6 Hz, Sensitivity (SPL): 90.0 dB