Features: 1.Onboard ESP-01 WiFi module and high performance microprocessor STM8S103. 2. The module has 2 working modes: Mode 1: The phone is directly installed on the WiFi module. Mode 2: Equipped with a mobile phone and WiFi module on the router Additional features: It can also be used as a USB relay when the ESP-01 is pulled out. 3. Transmission distance: In an open environment, when the mobile phone is installed on the WiFi module, the maximum stable transmission distance is 100M. When the WiFi module and the mobile phone are simultaneously carried on the router, the transmission distance depends on the signal strength of the router. 4.Use Smartcongig technology to complete the account and password configuration on the APP ESP-01 WiFi module on the mobile phone, and configure the username and password memory functions. 5. On-board 5V,10A250V AC 10AV30V DC relay, which can continuously pull 100,000 times, with diode discharge protection and short response time. 6.Board mode selection and real-time working status indicator. 7. Reserved UART debug interface and STM8 SWIM program download interface. Specification: Model:ESP8266 Channel:Dual Channel Board size: 59 x 40mm/2.3 x 1.6in Weight: Approx.36g/1.3oz Package list: 1 x Dual Channel WiFi Relay Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.