1. Onboard and stable ESP32-WROOM-32E module, large capacity 4M Byte Flash 3. Onboard DC-12V to 3.3V power supply circuit, the power supply mode supports DC-12V 4. Onboard reset button and IO0 programmable button 2. The I/O port and UART program download port of the ESP32 module are all lead out to facilitate secondary development. 5. ESP32 supports the for IDE Compilation Tool And Provides Reference Programs In The for Development Environment. It Has 16 5V Relays On Board And Outputs Switching Signals. It Is Suitable For Controlling Loads With Operating Voltages Within AC250V/DC30V., Manufacturer: Akfldms