beyerdynamic Phonum, Hands-Free Telephone, For conference calls via the Internet, Bluetooth technology for more freedom of movement, USB port as secondary interface, Range up to 10 m, Battery life up to 12 hours, Audio codec: Low Complexity Subband Codec (SBC), Display of operating status, microphone mode, battery status, Operation via touch sensors, Charging time approx. 3 hours, Lithium-ion batteries, Sound pressure level: 75 dB at 1 m/1 Wrms, Frequency range microphone: 150 to 6800 Hz, Frequency range speaker: 100 to 14000 Hz, Audio algorithms: Echo Cancellation (AEC), Noise Reduction (ANC)., Bluetooth: BT4.2, class 2, Supported profiles: HFP, A2DP (device is sink), SPP (upload), Dimensions (L x W x H): 136 x 136 x 63 mm, Weight: approx. 450 g, Includes hard case and 1 m USB-C cable