Cordless stereo headset based on Bluetooth (class 2), passive noise cancellation through special ear cushions, high-quality speakers for voice and music playback, microphone with noise canceling, technology, volume control directly on the headset, busy indicator (via central indicator light), incl. USB charging cradle, Up to 10 hours of talk time, multipoint capability, NFC technology, on/off switch, microphone holder via magnetic contact in the headband, USB dongle for PC. Suitable for ST 40 (S0/UP0), ST 42 (IP), ST 45 (IP), ST 53 (IP), ST 54 IP and ST 56 (IP) each with BT module 40 or BT module 50.