Cadence Acoustics S1W15D4.v2 4 Ohm 1200W 15" Subwoofer Power handling: Peak: 1200 W / RMS: 600 W "M" Style Double Laminated Foam Surround for High Speed Bass Response Expanded and Rolled Steel Basket Magnet Motor Heat sink with Heat Pump Cooling Technology System Impedance: Dual 4 Ohm