With its advanced functionality and cutting edge design the Z9 Bluetooth Headset offers a range of differentiating features which ensure crystal clear wireless enabled communication. Such features include: Two microphones for pure speech World class Digital Signal Processor (DSP) software Echo suppression and noise cancellation Near-field sensing with Automatic Gain Adjustment Innovative tie clip for attaching to shirt, cuff, etc when not in use. The ability to pair with multiple devices On-the-fly switching between devices Abnormal Disconnection Notification Firmware upgradeable by USB A different ring tone for contacts and unknown callers Auto connection and reconnection Up to 7 hrs talk-time or 180 hrs standby