Dual standy MS Multipoint Bluetooth Handsfree Speakerphone This product support one speakerphone connect to two phones. Support secure simple phones.Advanced echo and noise cancellation. Full duplex and high performance speaker. With advanced built-in microphone which adopts D.S.P. solution for echo cancellation and noise suppression, this speakerphone creates an outstanding full duplex sound quality for you. Bluetooth: version 2.0, class 2, 10 meters. Bluetooth profile: speakerphone & hands-free profiles. Operating frequency band: 2.4GHz to 2.48GHz unlicensed ISM band. Rechargeable battery: 3.7V DC, 650mAH. AD/DC charger: DC 5 to 6V, 400mA.