Note1: Some logistics channels (such as Aliexpress Direct/ Special Line-YW China Post Registered Air Mail/SF eParcel) are not allowed to carry batteries. In order to ensure that the goods can be sent out, we will take out the batteries and then deliver . Please understand.If you have any questions, please consult the customer service. Note 2: SNZB 01/02/03/04 must be used with Zigbee Bridge. SONOFF SNZB-01 Zigbee Wireless Switch is a mini and exquisite ZigBee wireless smart switch replying on SONOFF ZigBee Bridge that allows you to reach the purpose of scene linkages between ZigBee devices (SONOFF BASICZBR3 DIY smart switch and S31 Lite zb smart plug) and Wi-Fi devices. SONOFF SNZB-02 is a ZigBee temperature and humidity sensor that can seamlessly work with SONOFF ZigBee Bridge to track and record the temperature and humidity change in your home, which all real-time readings can be checked on eWeLink APP. SONOFF SNZB-03 is a ZigBee motion sensor is an extra-handy smart device for placing anywhere in your home to detect motion and trigger alarms. SONOFF SNZB-04 is a ZigBee two-in-one wireless door/window sensor that can be put on your door or window to tell you with an alert notification if your door or window is opened or closed, adding an extra layer of security to your home. SONOFF ZigBee Bridge is the heart of smart home that enables you to remotely manage a variety of ZigBee devices and sensors for monitoring and control purposes of home, and allows you to create smart scenes to make Wi-Fi and ZigBee smart devices communicate to access a smarter home and control them all using the eWeLink APP.