NEW Upgrate WIFI GSM Alarm System. Built-in backup battery, it can stand by for 8 hours if the external power is off,and it can still work about 8 hours. (built-in siren.). Siren output:<500mA. a regular SIM card supporting 2G/GSM, and a Wi-Fi 802.11 b/g/n(2.4GHz) network connection.
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