USB Headset built in Digital Sound Stereo, In line Volume + Call control, Noise Cancelling Microphone while Enjoy Multi-Media Music. Don't Compare This Professional Headset with General Headsets. All Day Wearing Comfort, Compete with Plantronics and Jabra GN netcom High-Grade Headsets for Call Center, Telemarketing, Customer Representative. Multi Year Warranty, 20 Year Proven Quality in The World. Complete Digital sound card embedded (Extreme Stereo Music Sound) Plug in Play USB 2.0 compliance works with soft phones, MS Lync, Skype, Google Talk... Built in-line control board has the Mute and Receiving volume adjustment. Noise cancelling microphone reduce background noise. Specially for VOIP calls.