Please check the following before using this device:1. Your smartphone or tablet has been connected to a 2.4G WiFi that can access the Internet (5G WiFi is not supported yet) 2. Turn on Bluetooth on your phone 3. If you use an Android phone or tablet, the system must be version 4.0 or above. 4. When using an phone or , you must be to access the and download the APP 5. If your wireless router is set up with address filtering, please enter the router background to turn off the filtering function. When using this device, it must be used in conjunction with a Zigbee gateway. Product instructions: 1 Search "Tuya Smart" in and major application markets 2. If prompted for permission during the installation process, please select Allow. 3 Register an account and log in to Tuya Smart APP 4 Follow the instruction manual for correct wiring. Installation with power on is strictly prohibited. 5 After completing the wiring, turn on the power. The device's default setting for incoming calls is off. You can change the setting in the APP to turn on or hold incoming calls. Specifications:Input voltage: DC 5V/85-250V AC Maximum power: 2200W /10A Wireless Standard: 2.4GHz b/g Working temperature: -20~70 degrees Celsius Product Size: 81x76x28,mm Colour:White Material:abs Package Contents: 4 x Smart switch Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.