The CM-804i is a double ear hook sub minature Omni Directional Microphone headset. 60-15,000 KHz.Supplied with 4 pin mini XLR connection. optional cables available with different connectors. Frequency response: 60Hz - 15kHz Polar Pattern: Omni-Directional Impedance: 1.8kΩ Sensitivity (at 1kHz): -64±3 dB* (0.63mV)*0dB Max. SPL for 1% THD: 130dB