SD-3 12 D4 - Sundown Audio 12" 500W RMS Dual 4-Ohm SD Series Subwoofer SD-3 12 D4 - Sundown Audio 12" 500W RMS Dual 4-Ohm SD Series Subwoofer Power Rating: 500W RMS 0.5 ft^3 Sealed Box Requirement Cut-Out Diameter: 11.0" Top Mount Depth: 5.0"