1.Compatible Bluetooth specification:V2.1+EDR 2.Standby time:600hours 3.Working ... meters 4.Talk time 8-10hour Product Features:1,Compatible Bluetooth Specification V2.1+EDR 2,Operating Frequency Band: 2.4GHz ... ,Support Multiple paired,allows a speakerphone connect to two phones. (Memory Up to 8 Bluetooth Phone paired) 6,Integrated with echo cancellation ...