1、This product is different from the alarm on the market. In addition to the power failure alarm, the call will also alarm. It is a dual function alarm. 2、The power failure alarm is also called the power failure alarm and the machine room power failure alarm. When the power grid is cut off or the power supply cable is cut, an alarm will be sounded immediately until the power is restored or the battery is exhausted. 3、Applicable to computer rooms, electric duty duty rooms, power companies, etc., can also be used for residential households to monitor burglar alarms when wires and cables are stolen. 4、The power indicator of this product can make the power supply status of the power grid clear at a glance; the high voltage resistant design can work at 260V for a long time, even if the grid voltage exceeds the standard in the middle of the night, it is 5、The drawer type battery cover switch is convenient, and the battery can be easily replaced; can use the ordinary battery. Features: This product is different from the alarm on the market. In addition to the power failure alarm, the call will also alarm. It is a dual function alarm. The power failure alarm is also called the power failure alarm and the machine room power failure alarm. When the power grid is cut off or the power supply cable is cut, an alarm will be sounded immediately until the power is restored or the battery is exhausted. Applicable to computer rooms, electric duty duty rooms, power companies, etc., can also be used for residential households to monitor burglar alarms when wires and cables are stolen. The drawer type battery cover switch is convenient, and the battery can be easily replaced; can use both the ordinary battery. Specifications: Condition: Brand New Material: ABS Color: White Package Weight: Approx.100g/oz Alarm mode: It can whistle alarm when the grid is cut off or the power supply cable is cut, until the power is restored. The alarm volume is ≥115 decibels. Power indicator: The power supply status of the grid can be seen at a glance. Battery life: Normal battery ≤ 2 years in standby state Replacing the battery: The drawer type battery cover switch is convenient and can be easily replaced. Working environment: temperature -30°C ~ +60°C Relative humidity ≤ 85% RH. Package List: 1 * Power Off Alarm Sensor (Battery is not included)