1.Tuya Smart ZigBee SOS Sensor:A Tuya ZigBee Wireless Gateway Hub is a must to work with the SOS sensor,as well as a variety of ZigBee smart products, which is proved to be and control center for smart homes and plays an irreplaceable role for all ZigBee products and realizes the whole intelligent linkage of your house.Simply add the sensor into the ZigBee hub after adding the hub into Smart Life/Tuya App. 2.One click alarm for emergency help and Smart Life Tuya App compatible for smart phones push notifications by receiving the alarm information from the sensor on smart phones anywhere,anytime needed. 3.Wide applications with its mini design and fits for the elderly and children particularly by pressing it gently to send the emergency help.No complex operations and buttons. This product must be used with Zigbee Gateway (not included). Without Zigbee Gateway, it will not work. The appearance and color of different batches of products may be different, which will not affect the use.