The Savi W440-M is a Microsoft Lync compatible,portable DECT headset system with an ultra-light headset with three wearing styles and the wireless freedom to multi-task up to 300 feet from your desk. And you can change the hot swappable battery mid-conversation for unlimited talk time. Advanced audio technology and world class sound quality are perfect for campus-like business environments using a laptop for voice calls and multimedia. Additional battery sold separately