Mode Com MC-10B. Wireless range: 10 m, Bluetooth version: 2.0+EDR. Headphone frequency: 20 - 22000 Hz, Headphone sensitivity: 80 dB, Acoustic system: clip-on. Microphone sensitivity: -50 dB. Operating temperature range (T-T): -10 - 50 °C. Charging time: 240 min