Technical Parameters:Sensitivity: 52dBImpedance: 2.2 KΩ-30%Flat rate: 20 ~ 16.000HZOperating voltage: 10V (TVU)Reference operating voltage: 4.5VCurrent consumption: 0.5mA (max)Sensitivity attenuation: ≤-3dB at 2-1.5vPacking: 10Pcs