Pyramid WX81X 8-Inch 300 Watt Subwoofer High Power Blue Paper Cone Woofer - Heavy Magnet Structure - Magnet Weight: 50 oz. Bumped Yoke Plate for Extended Excursion - Impedance: 4 Ohm - Mounting Depth: 3.27'' Specially Treated Black Rubber Edge Suspension - 150 Watts RMS/300 Watts Peak Vented Motor Structure - Overall Diameter: 7.91'' 1.5'' High Temperature Aluminum Voice Coil - SPL @ 1W/1M: 96dB