- The control hub is pluggedtothe electrical socket and acts as a receiver from the rest ofthe sensors readings. It connects directly to the route through wifi. - The group of sensors connect to the control hub through Zigbee. This set contains, besides the control hub: 2 window & door sensors, 2 motion sensors and one wireless switch. - The Mi Smart Sensor Set enables an additional level of automation in your house. Now you can set the rules of when your devices will work, not work, when functions are activated, etc. based on sensor readings. - You can add more sensors bought separately to monitor more and more rooms. Check availability by country. - All rules and automations are set up directly on the Mi Home App through a very simple interface. Once this set is installed, other Xiaomi products in your account will be connected to the Mi Smart Sensor Set and you will be able to customize your own automated house.Lights turning on when you pass by, purifiers starting when you close a door, etc. the possibilities are endless.