Imou Siren, Wireless siren, Indoor, 250 m, 433 MHz, 85 dB, Red, White85dB Local Siren and Light When the Imou detector is triggered, the Siren will sound 85dB alarm and flash the LED light to scare off intruders. 100% Wire-free Powered with batteries and connected by Airfly, you can place it anywhere Low Power Consumption Powered with four CR123A batteries which can be used for up to one and a half years. Tamper Protection When Siren is removed from the wall, a local alarm will be triggered. The Alarm Station will send a tamper alert to your smartphone. Smart Home Security Solutions Protect your home at every corner.