The B159 extends the uses of the typical conference phone by allowing you to switch between and combine three connectivity technologies—analog, mobile, and USB—extending your mobile’s speakerphone capabilities. The USB connection allows the phone to be used to make VoIP calls so you can hold group calls over the Internet. The B159 is ideal in larger settings as you have the option of connecting to an external PA system and adding expansion microphones that effectively double the voice pickup range. A wireless headset can also be connected for lecture situations enabling mobility while still delivering high-quality sound.