Lenovo Wireless Stereo Headset (4XD1Q30302) - Capacity: 640 mAh, Connectivity: Bluetooth, Frequency Range: 20 Hz - 20 kHz, Impedance: 32 Ohm, Driver: 40 mm, Battery Charging Time: 2 hours, Play Time: 60 hours, Wireless Operating Distance: up to 30 m, 3 Microphones for ENC, On-Ear Controls