Jabra Evolve 40 Mono MS - Professional Unified Communicaton Headset Passive noise cancellation to eliminate background noise and provide amazing sound on both ends of the call Integrated busy light automatically turns on during a call to let others know you are busy Easily transfer your Skype for business and Lync PC calls to your smartphone for calls on the go Option to connect to devices via USB or 3.5mm Jack Works with all the most popular online voice call services