Jabra 6399-823-109, Evlv 40 Ms Stereohd Audio, Black, Microphones Frequency 100 - 10000 Hz, Connector 3.5, Material Leather, Used Portable electronics,computer, Over-the-Head, Input Power (mW) 10, Connectivity 3.5mm jack, Wireless or Wired, Speaker, Microphone Jacks. The Jabra EVOLVE 40 MS Stereo Headset is a headband-style headset that comes with a control unit for easy operation as it allows you to use the functions like volume and mute and the ability to end and answer calls.