... voltage Protection:Activating time≤ 1sData Response Time:≤ 10s (under normal GSM network status)Working Voltage & Current:7.5-12V, 1. ... 5AElectrical Source: AC 110-220v, 50HzBackup Batteries:60mAh, 3.7VWorking time:≥ 4 hoursWorking Environment:Temperature ... ,school,library,bank,financial office,office,computer room. 2012 GSM home phone Multi-functional Telephone Alarm System