Your first Converge Signal delivery will include the following items:
Each box should contain within 1 to 4 Converge signal devices. Each sensor has a magnet that will keep them off. As soon as you remove the magnet from the sensor, the led will start flashing white, which means the sensor is active and recollecting data.
Putting the magnet back in the sensor won't turn it off, but don't worry, the battery life could last months or even years.