Traditional Culture Encyclopedia - Hotel franchise - What's that glowing red on the roof of a hotel room?

What's that glowing red on the roof of a hotel room?

This is a smoke alarm. When there is a fire, it detects the sprinkler. If the place where the red light flashes is not on the roof, you may want to pay attention to whether it is a camera. Another good way to distinguish the camera from the temperature alarm is that the red light flashes at the same frequency, while the camera is always red and does not flash.