Plantronics H251N SupraPlus NC Headset Wideband audio for more natural sound and clearer conversations Fully compatible with standard band environments Premium audio assures quality customer communications Ultra noise-canceling screen out background noise, reducing distraction Over the head, all-day comfortable design for intensive use The SupraPlus brings new standards in all-day comfort and reliability to telephone professionals Enhanced receive-side audio quality, intelligent flexible boom and stylish design provide greater headset flexibility Must be used with a Plantronics USB-to-headset adapter or headset amplifier Plantronics offers monaural or binaural versions with either voice tube or noise-canceling microphones