1. On-board and stable ESP-12F wifi module, large-capacity 4m bytes flash memory; 2. The power supply mode supports DC7-28V / 5v; 3. The first reset button of the wifi module on the board; 4. ESP-12F supports the use of development tools such as eclipse / for ide, and provides reference programs in the development environment; 5. There are 8 5v relays on the board, which are used to switch output signals and are suitable for controlling loads whose working voltage is in the AC range. Onboard power indicator and relay indicator. Material:plastic colour:Green Package Contents: 1 x WIFI 8 Channel 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 picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.