The SwitchBot Contact Sensor allowsyou to record the moment of entry / exitthrough the door or window,opening and closingthem andthe level of light intensityin the rooms where it is located. It consists of two elements, attached close to each other on objects such as doors and windows. It works on the principleof a magnetic connection, as soon as it is broken, the sensor will send a notification to your mobile device, affecting your sense of security and comfort.