1、Power indicator: The power supply status of the grid can be seen at a glance. 2、Alarm mode: It can whistle alarm when the grid is cut off or the power supply cable is cut, until the power is restored. 3、Monitoring voltage width: AC175V ~ 265V, a wider range of applications, not only for towns, but also for remote villages where power supply voltage is extremely unstable. 4、Battery undervoltage alarm: Prevents false alarms caused by battery failures not being discovered. 5、Replacing the battery: The drawer type battery cover switch is convenient and can be easily replaced. Description: The power failure alarm is also called power failure alarm and machine room power failure alarm. When the power grid is cut off or the power supply cable is cut, the alarm will be whistle immediately, and the alarm will not stop until the power is restored or the battery is exhausted. In the computer room, electrician duty room, power company, etc., can also be used for residential households to monitor the burglar alarm when the wire and cable are stolen. The flow automatic charger can use both ordinary batteries and rechargeable batteries; when using rechargeable batteries, the standby life is up to 10 years, which can prevent false alarms caused by battery failures being undetected. Features: Power indicator: The power supply status of the grid can be seen at a glance. Alarm mode: It can whistle alarm when the grid is cut off or the power supply cable is cut, until the power is restored. Automatic charging: Built-in trickle automatic charger for both regular and rechargeable batteries. Battery life: Normal battery ≤ 2 years in standby state, rechargeable battery ≤ 10 years. Battery undervoltage alarm: Prevents false alarms caused by battery failures not being discovered. Replacing the battery: The drawer type battery cover switch is convenient and can be easily replaced. Specifications: Condition: Brand New Material: ABS Color: Shown as picture Battery model: DC9V (1 GF22 battery not included) Alarm Volume: ≥115 decibels. Working environment: temperature -30°C ~ +60°C Relative humidity: ≤ 85% RH. Package Weight: Approx.60g/2.1oz Package List: 1 * Power Off Alarm Sensor (Battery is not included)