1. The 4-channel 30A relay development board is a development board based on the ESP32-WROOM-32E module 2. I/O ports are fully led out, supporting DC7-28V/5V power supply 3. Onboard programmable buttons, LEDs and relays facilitate developers to quickly conduct prototype verification and development, and bring more possibilities for loT control scenarios 4. Provide SDK ESP-IDF code. After burning the program, you can directly remotely control the onboard LED and relay with your mobile phone, and have functions such as WiFi network configuration and factory reset (contact customer service) 5. ESP32 supports the use of development tools such as for ArduinolDE/VSCode/Tonny: for Arduino code and ESP-IDF code are provided(contact customer service) Name:Relay module The product appearance and printed words may vary depending on the batch, but this does not affect use. Colour:Blue Material:PCB Package Contents: 2 x Relay Module Kit Only the above package content, other products are not included. Note: Light reflection 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.