Specification: Model No:TD-850K Exit Throat Diameter: 50.8/2 mm/inchRated impedance: 8 ohnPower handing capacitycontinuous program above 1.2KHz: 180 WattAES above 1kHz: 90 WattSensitivity: 109 dBFrequency Range: 50-2000 HzMinimum Impedance: 8.8ohm at 3500HzVoice Coil Diameter: 74.4/3 mm/inchBL Factor: 12 T.MFlux Density: 1.85T