Polycom SoundStation 2W EX Wireless 2.4 GHz Conference Room Phone, full duplex for similtaneous 2-way conversation, 2.4 GHz WDCT digital spread sprectrum radio, 64 bit encryption for wireless security, 150ft wireless range, rechargeable Li-Ion extended battery - up to 24 hours talk time / 160 hour standby time, portable console charger with 3 hour recharge, cell phone dialing through headset connection ideal for rooms without a telephone line, backlit graphical display, extended room coverage with addition of external microphones below 2200-07840-001.