1. Speark unit: 53mm
2. Headset impedance: 20ohm +/- 15%
3. Headset frequency response: 20-20KHz
4. Microphone: omnidirectional
5. Mic frequency response: 50-10KHz
6. Mic sensitivity: -42 +/- 3 dB
7. Input voltage: 5V
8. Output power: 20mW (1KHz 0dB)
9. Cable length: 1.67m