Boss CH15 15-Inch Subwoofer Power Peak, 600 Watts; RMS Power, 300 Watts Cone Material, Metallic INJECTION; Magnet Structure, 80 oz Voice Coil Size, 2-Inch Efficiency 1 Watt/1 Meter, 96dB; Frequency Response, 22Hz-2kHz; Impedance, 4 ohm Mounting Depth, 6-Inch