UC & Skype for Business: For professionals using Skype for Business or who require an excellent hands-free communication solution for phones and all UC platforms (Cisco, Avaya, IBM, etc.) HD Sound: Powered by a neodymium speaker for legendary Sennheiser HD sound to ensure a clearer and more natural audio experience Ultra Noise-Cancelling Technology: Filters out all unwanted background noise for crystal-clear conversations State-of-the-Art Materials: Stainless steel hinges, brushed aluminum parts, & Vectran reinforced cables defend your headset against everyday use In-Line Call Control Unit: Answer or end your calls, control the volume, mute your mic and redial calls - directly from your headset All-Day Comfort: Large leatherette ear-pads and unibody headband construction are built for maximum strength at stress points to ensure a comfortable experience ActiveGard Technology: Ensures protection against acoustic injury caused by sudden sound bursts on the line