Technical specifications:Megaphone diameter: 40 millimetersFrequency range: 20-20.000HzSensitivity: 105dB 3dBDistortion: 2% THDMagnetic dimensions: F15.5x2.0 millimetersImpedenza: 32 Ohm 15%Input power: 30mW (max)Microphone Sensitivity:-58dB 3dB