Product Specifications Nominal Diameter: 305 MM / 12" Chassis Type: Aluminium Die Casting Magnet Type: Ferrite Magnet Grade: Y35 / 185*20 Spider: AX Cloth Voice Coil Diameter: 76.2 MM / 3" Voice Coil Material: Copper Wire / Glass Fibre / Till RMS Power: 400 Watt AES Power: 440 Watt Impedance: 8 Ohms Surround Material: Cloth Edge Sensitivity: 97 dB Best For Medium Bass Frequency DJ Sound System