Rat.Impedance 4,8,16,32,64,100,150(±15%)Ω Rat.Noise Power(Max) 0.25W Rat.Resonant Freq(fo) 750±25%(Hz) Rat.Freq.Range f°-3000Hz Rat.Char Sensitivity Level 84±3dB D(mm) Ø27 H(mm) 3.0