Jabra M5390 USB headset is a Bluetooth headset that connects simultaneously to mobile phones and PC softphones (via the enclosed PC USB Bluetooth adapter). Jabra M5390 USB headset combines the sound and range performance known from office headsets with the convenience of a mobile headset.Based on next generation Bluetooth technology, it offers true wideband audio when used with the A335w USB Bluetooth adapter and a softphone. And the extended wireless range allows users to answer calls up to 70 meters from their desks. The design and wearing style is optimized for office staff, managers and specialists who spend most of their time in the office – and less on the go. For optimum call clarity in loud office environments, the microphone is placed close to the users mouth and features noise cancelling technology.The A335w USB Bluetooth adapter is compliant with a wide range of PC based softphones such as Microsoft Office Communicator 2007, Cisco Communicator, Skype etc.