Aura SoHo Plus Conference Phone ensures everyone can be heard even in a large conference room with the included three built-in and two external microphones. Total of five microphones and 5 watts of loudspeaker volume provide 360-degree coverage for a 20' x 20' room. Patented, SoundClear DSP (digital signal processing) chip provides noise and echo cancellation to deliver unprecedented clarity of sound. With full duplex, you can hear the other party while you're speaking. Modular sleek design allows growth as your needs change. Conference phone will connect with your analog phone line (PSTN). Optional Bluetooth Module (sold separately) allows you to pair your cell phone to the Aura SoHo Plus for professional conference calls. Optional Digital Module (sold separately) allows you to connect to a PBX system without needing a whole new conference phone. Wall-mountable conference phone also includes 18' 120/240 VAC wall adapter and phone interconnected box, RJ-11 phone cord and wall adapter.