Let the 5 smoke detectors and the carbon monoxide detector in this pack work together by connecting them to the included Smart Bridge. This allows you to hear if a fire or dangerous gas is developing in several places in the house. After you connect the detectors, you'll receive notifications via the app on your smartphone when smoke or carbon monoxide is detected. You'll also receive a notification via the app when the battery needs to be replaced or if the sensor no longer fully functions. If it detects something, you'll hear a 85dB noise indoors. Make sure to test if the detectors still work via the test switch once a month.