SoundQubed HDC3.118 18 inch Dual 2 ohm Subwoofer 1500W RMS 18" Subwoofer with a 3inch Dual 2ohm Copper Voice Coil The HDC3 has a 9.25 inch diameter multi-layer composite spider 10 Gauge Direct Voice Coil Lead Wires 1500 Watt RMS-4500 Watt Peak