1. ESP-12F and stable wifi module on board, 4Mbytes large capacity flash memory; 2. The power supply mode supports DC7-28V / 5v; 3. The first wifi module reset button 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 operating voltage is in the AC range. Onboard power indicator and relay indicator. Material: plastic color: green Package Contents: 3 x 8 Channel WIFI Relay Module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in a little different from the real thing. The measurement allowed error is +/- 1-3 cm.