Sennheiser PC 26 Call Control USB Single-Sided Headset Sennheiser sound Noise canceling clarity USB Plug and Play Convenient 3-in-1 control Keep one ear free Sennheiser sound - the integrated USB soundcard and quality speakers ensure every word comes through crystal clear Noise canceling clarity - not only will your voice come through in crystal-clear quality,the noise canceling mic is also ideal for your device's speech recognition function USB plug & play - simply plug into your computer's USB port to start phoning over the net Convenient 3-in-1 control - fully adjust the volume/mute and control your phoning session directly from the headset Free HeadSetup software - conveniently download Sennheiser software for easier control of your softphone from the headset Keep one ear free - the single-sided design keeps you in touch with your surroundings while you chat Fully flexible boom arm - adjust the microphone for optimal voice pick-up and comfort