General Specifications Nominal diameter 254mm / 10in Power rating 350watt-700watt Nominal impedance 8 ohms Sensitivity 95DB Frequency range 55-4000HZ Chassis type Cast aluminum Magnet type Ferrite Magnet size 170x85x20mm Magnet weight 1.64kg / 57.9oz Voice coil diameter 75.5mm / 3in Coil material CCA -W Number of layers 2 (Outside) Former material Kapton Cone Material Paper Surround material Cloth Spider Single X-max 3 mm / 0.12in Gap depth of 8 mm / 0.31in Voice coil winding width 15 mm / 0.59in Net Weight: 4.95kg / pcs Gross Weight: 5.31 / pcs Packing Size: 26.5 * 26.5 * 12.5cm / pcs