... off warning function: SMS to inform users if power failure.9. Intercom function: can communicate with the scene people ,two ... silence and siren sound15. Optional built-in battery, AC and DC automatic shift, automatically recharge.16. Wireless alarm system, no ... .Technical Specification: Standby Current: 80mA Working Current: 300mA Power Supply: DC 9-12 VOperating Temperate: -10°C ~ +40°C GSM Frequency: ...