When the WiFi module and the mobile phone are running on the router at the time, the transmission distance depends on the signal strength of the router. Onboard 12V, 10A // 250V AC 10A // 30V DC relay, which can be activated continuously for 100,000 , with diode discharge protection, and short response time. Smartcongig technology to complete the account and password configuration on the mobile phone APP ESP-01 WiFi module, and configure the user name and password memory function. Single board mode and real-time working status indication. Reserve UART debugging interface and STM8 SWIM program download interface. The 12V Dual WiFi relay module uses ESP-01 as the WiFi module and is with 8-bit MCU . With a simple configuration process, the wireless control of 2 relays can be realized through the mobile phone APP. Onboard ESP-01 WiFi module and high-performance microprocessor STM8S103. The module has 2 operating modes: 1: The mobile phone is directly installed on the WiFi module. 2: Equipped with a mobile phone and WiFi module on the router Additional function: When ESP-01 is unplugged, it can also be used as a USB relay. Transmission distance: In an open environment, when the mobile phone is installed on the WiFi module, the maximum stable transmission distance is 100M. The color of some components of the product may change, but the effect remains the Colour: blue Material: metal Package Contents: 1 x ESP8266 12V WiFi Relay Only the above package content, other products are not included. Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.