Double-layer USB expansion port:Output 5V 1A      Double-layer USB interface:They are I2C/UART functions      Functionally based on ES32-WROVER (WIFI/Bluetooth) module, 5V relay, buttons, RTC, battery-powered interface, DC socket (5-12V input) battery-powered switch, USB expansion port I2C/UART, USB expansion port are designed The output power supply can supply power and control the current of equipment below 1A.      The back side retains the TF card socket in the same position as the Raspberry Pi, which is a self-popping card socket, which is convenient for plugging in and out.      Chip:ESP32-WAROVER      LCD:3.5 inch capacitive touch screen     ST7796 FT6X36/ILI9481 GT911      USB TO TTL:CH9102F      Relay:HFD3 5V 2A      Relay connector:5.08      DC-DC input:5-12V      DC Block Specifications:5.5X2.1      TYPE-C input:5V      USB output:5V 1A      Battery Specifications:3.7V lithium battery      Battery switch:Toggle Switches      Button:RST button, custom button      RTC:PCF8563      Extension pin:2.54 2X20      Colour:black      Material:Plastic + Metal            Package Contents:      1 x host      1 x line            Only the above package content, other products are not included.      Note: Light shooting 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.