The Sennheiser BW 900 is a business class, over-the-ear Bluetooth headset that sports a 300 foot range as well as compatibility with a variety of different phones. Smart phones, desktop phones, mobile phones, PDAs, VoIP enabled computers, basically any phone that is Bluetooth capable. Talk time can be limitless with the use of an optional second battery which can be exchanged mid-call if necessary. Headset controls include volume adjust, mute, call answer/end, and, Adaptive Intelligence digital signal processing remembers headset parameters for each user's preferred settings. Voice recognition is also supported and it can also work with devices like the Zoom Switch to take VOIP calls on a computer that isn’t Bluetooth enabled.