1. Onboard and stable ESP-12F module, large capacity 4MByteFlash 2. The module's I or O port and UART program download port are all led out to facilitate secondary development 3. Onboard DC power supply circuit, power supply mode supports DC5V or 12V or 24V, power supply power should be higher than 20W 4. Onboard reset button and IO0 programmable button 5. ESP32 or ESP8266 supports for IDE compilation tools, providing reference programs under for development environment 6. Onboard 32-way 5V relay, output switch signal, suitable for control, working voltage is within AC250V or DC30V load 7. main control replaceable design (The product appearance and printed words depending on the batch, but this does not affect use) Material: PCB colour: Package Contents: 1 x 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 the picture a little different from the real thing. The measurement allowed error is 1-3cm.