1. On-board mature and stable ESP-12F WIFI module, 4M flash capacity. 2. The WIFI module input / output port and UART download port are all led out to facilitate secondary development; 3. Reset button of built-in WIFI module. 4. ESP-12F is compatible with development tools such as / IDE. 5. 2 to 5V relays, output switch signal, suitable for controlling AC working voltage Charge within 250V / DC30V. Integrated power indicator, 1 programmable LED and relay indicator. colour: green Material: PCB size: 78x47mm Package Contents: 1 x ESP8266 ESP-12F WIFI Relay Module Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.