Lenovo ThinkPad X1 Active Noise Cancellation Headphones, Bluetooth 5.0, Battery Capacity 800 mAh, Battery Charging Time 3h, Play Time 14h, Wireless Operating Distance 10m, Impedance 32 ohm, Sensitivity > 111 dBm +/- 3 dBm, Distortion 5%, Microphone: 4 x analog microphones: Omni- directional