Serene Innovations CentralAlert™ CADX
Install device on existing door chime or intercom door announcer for vibration detection. When someone rings your door bell, it detects vibration and sends a wireless signal to trigger the CA360 to alert. Or, you can attach the CA-DX to the inside surface of your door to detect the knocking on your door.
*With this method, electrical signal from your doorbell terminal activates CA-DX