Features?3-inch,fibreglass inside-outside AL voice coil700 Watt continuous program power handling98 dB Sensitivity65-3500 Hz Frequency rangeSpecificationNominal diameter? 250 mm/10 inPower rating? ? ? ?350W(AES)Nominal impedance? 8OHMSensitivity? ? ? ? ? ?98 d BFrequency range? ? ? 65-3500 HzMagnet weight? 78 ozVoice coil diameter? 75.5 mm/3 inDesignCoil material? ALFormer material? Glass fiberCone material? PaperSurround material? ClothSuspension? single?Kind of layers? outside/insideNumber of layers 2Gap depth? 10.0 mm/0.39 inVoice coil winding width? 12 mm/0.47 in1: 2 hours test made with continuous pink noise signal within the range Fs-10Fs. Power calculated 2: on rated nominal impedance. Loudspeaker in free air.3:Power on Continuous Program is defined as 3 dB greater than the Nominal rating.4:Applied RMS Voltage is set to 2.83 V for 8 ohms Nominal Impedance. http://www.chinasoundspeaker.co...h-mid-range-speaker.html