AKG C451 B condenser small diaphragm microphone.
SPL: 135dB (0,5% THD)
Dynamic range: 117dB
Frequency response: 20Hz - 20kHz
Noise level: 18dB
Sensitivity: 9mV
Signal to noise ratio: 76dB
Impedance: 200Ω
Polar pattern: Cardioid
Operating voltage: 9V - 52V