Sennheiser SC 660 USB ML (504553) - Double-Sided Business Headset | For Skype for Business | with HD Sound, Ultra Noise-Cancelling Microphone, & USB Connector (Black) Double-sided headset (sc 660) Skype for business, HD voice clarity Connect to a Softphone via USB Active Guard technology protects against acoustical shock Ultra noise cancelling microphone Call control unit answer/end calls, control volume, Redial and reject incoming calls Premium dual-sided wired headset optimized for Microsoft Lync, with built-in call control unit Designed for quality-conscious contact center and UC professionals requiring outstanding sound performance while maintaining contact with surroundings Comfortable fit that lasts all day and a solid sense of quality Built to sound superb, look stunning and outlast the competition Conversations are crisp and clear for speaker and listener-even in noisy environments Century is crafted with high-end materials to ensure maximum durability and design quality Stainless steel hinges, brushed aluminum parts and Kevlar cables defending headset against everyday use Large leatherette ear-pads to the unibody headband construction for maximum strength at stress points